diff --git a/apps/stage-tamagotchi/src/renderer/components/InteractiveArea.vue b/apps/stage-tamagotchi/src/renderer/components/InteractiveArea.vue
index 0cd08f6a5..0271cf118 100644
--- a/apps/stage-tamagotchi/src/renderer/components/InteractiveArea.vue
+++ b/apps/stage-tamagotchi/src/renderer/components/InteractiveArea.vue
@@ -1,4 +1,5 @@
 <script setup lang="ts">
+import type { ChatToolCallRendererRegistry } from '@proj-airi/stage-ui/components'
 import type { ChatHistoryItem } from '@proj-airi/stage-ui/types/chat'
 
 import { errorMessageFrom } from '@moeru/std'
@@ -17,6 +18,8 @@ import { computed, onMounted, ref, watch } from 'vue'
 import { useI18n } from 'vue-i18n'
 import { useRouter } from 'vue-router'
 
+import JournalToolCallBlock from './chat-tool-renderers/journal-tool-call-block.vue'
+
 import { useChatSyncStore } from '../stores/chat-sync'
 
 const router = useRouter()
@@ -44,6 +47,10 @@ const TRAILING_NEWLINES_REGEX = /[\r\n]+$/
 const SEND_MODES = ['enter', 'ctrl-enter', 'double-enter'] as const
 type SendMode = (typeof SEND_MODES)[number]
 const sendMode = useLocalStorage<SendMode>('ui/chat/settings/send-mode', 'enter')
+const toolCallRenderers = {
+  image_journal: JournalToolCallBlock,
+  text_journal: JournalToolCallBlock,
+} satisfies ChatToolCallRendererRegistry
 const sendModeLabels = computed<Record<SendMode, string>>(() => ({
   'enter': t('stage.send-mode.enter'),
   'ctrl-enter': t('stage.send-mode.ctrl-enter'),
@@ -211,6 +218,7 @@ async function handleRetryMessage(index: number) {
         :messages="historyMessages"
         :sending="sending"
         :streaming-message="streamingMessage"
+        :tool-call-renderers="toolCallRenderers"
         @delete-message="handleDeleteMessage($event.index)"
         @retry-message="handleRetryMessage($event.index)"
       />
diff --git a/apps/stage-tamagotchi/src/renderer/components/chat-tool-renderers/journal-tool-call-block.vue b/apps/stage-tamagotchi/src/renderer/components/chat-tool-renderers/journal-tool-call-block.vue
new file mode 100644
index 000000000..c6874fb93
--- /dev/null
+++ b/apps/stage-tamagotchi/src/renderer/components/chat-tool-renderers/journal-tool-call-block.vue
@@ -0,0 +1,223 @@
+<script setup lang="ts">
+import { createToolResultError, MarkdownRenderer, normalizeToolResultText } from '@proj-airi/stage-ui/components'
+import { useJournalPreviewStore } from '@proj-airi/stage-ui/stores/journal-preview'
+import { Collapsible, ContainerError } from '@proj-airi/ui'
+import { computed } from 'vue'
+
+const props = defineProps<{
+  toolName: string
+  args: string
+  state?: 'executing' | 'done' | 'error'
+  result?: unknown
+}>()
+
+interface TextJournalArgs {
+  action?: string
+  title?: string
+  content?: string
+}
+
+interface ImageJournalArgs {
+  action?: string
+  prompt?: string
+  title?: string
+  mode?: 'inline' | 'widget' | 'bg'
+}
+
+interface ImageJournalResult {
+  imageUrl?: string
+}
+
+const { openImagePreview } = useJournalPreviewStore()
+
+function parseObject<T extends object>(value: unknown): T | null {
+  if (typeof value === 'string') {
+    try {
+      return JSON.parse(value) as T
+    }
+    catch {
+      return null
+    }
+  }
+
+  if (value && typeof value === 'object')
+    return value as T
+
+  return null
+}
+
+const parsedArgs = computed(() => parseObject<TextJournalArgs & ImageJournalArgs>(props.args))
+
+const isTextJournalCreate = computed(() => {
+  return props.toolName === 'text_journal'
+    && parsedArgs.value?.action === 'create'
+    && !!parsedArgs.value?.content?.trim()
+})
+
+const isImageJournalCreate = computed(() => {
+  return props.toolName === 'image_journal'
+    && parsedArgs.value?.action === 'create'
+    && !!parsedArgs.value?.prompt?.trim()
+})
+
+const textJournalMarkdown = computed(() => {
+  if (!isTextJournalCreate.value)
+    return ''
+
+  const title = parsedArgs.value?.title?.trim() || 'Journal Entry'
+  const content = parsedArgs.value?.content?.trim() || ''
+  return `# ${title}\n\n${content}`
+})
+
+const imageJournalMarkdown = computed(() => {
+  if (!isImageJournalCreate.value)
+    return ''
+
+  const title = parsedArgs.value?.title?.trim() || 'Untitled Image'
+  const prompt = parsedArgs.value?.prompt?.trim() || ''
+  const mode = parsedArgs.value?.mode || 'inline'
+
+  let footer = ''
+  if (mode === 'bg')
+    footer = '\n\n> **Scene Shift**: Setting this as the active background...'
+  else if (mode === 'widget')
+    footer = '\n\n> **Canvas Created**: Spawning an artistry widget for you...'
+  else
+    footer = '\n\n> **Sharing**: Sending a quick sketch to our chat history...'
+
+  return `### ${title}\n\n*${prompt}*${footer}`
+})
+
+const imageJournalResult = computed(() => {
+  if (props.toolName !== 'image_journal' || !props.result)
+    return null
+
+  return parseObject<ImageJournalResult>(props.result)
+})
+
+const resultText = computed(() => normalizeToolResultText(props.result))
+const resultError = computed(() => props.state === 'error' ? createToolResultError(props.result) : undefined)
+const formattedArgs = computed(() => {
+  try {
+    const parsed = JSON.parse(props.args)
+    return JSON.stringify(parsed, null, 2).trim()
+  }
+  catch {
+    return props.args
+  }
+})
+
+const imageMode = computed(() => parsedArgs.value?.mode || 'inline')
+const imageStatusLabel = computed(() => imageMode.value === 'bg' ? 'Updating Scene' : 'Generating image')
+const imageStatusIconClass = computed(() => imageMode.value === 'bg' ? 'i-solar:gallery-wide-bold-duotone text-emerald-500' : 'i-solar:camera-bold-duotone text-violet-500')
+const imageStatusBadgeClass = computed(() => {
+  return imageMode.value === 'bg'
+    ? 'bg-emerald-500/12 text-emerald-700 dark:text-emerald-300'
+    : 'bg-violet-500/12 text-violet-700 dark:text-violet-300'
+})
+
+function openGeneratedImagePreview() {
+  openImagePreview({
+    title: parsedArgs.value?.title || 'Generated Image',
+    url: imageJournalResult.value?.imageUrl ?? null,
+  })
+}
+</script>
+
+<template>
+  <Collapsible
+    :class="[
+      'bg-primary-100/40 dark:bg-primary-900/60 rounded-lg px-2 pb-2 pt-2',
+      'flex flex-col gap-2 items-start',
+    ]"
+  >
+    <template #trigger="{ visible, setVisible }">
+      <button
+        :class="[
+          'w-full text-start',
+        ]"
+        @click="setVisible(!visible)"
+      >
+        <div
+          v-if="state === 'executing'"
+          i-eos-icons:loading class="mr-1 inline-block translate-y-0.5 op-50"
+        />
+        <div
+          v-else-if="state === 'error'"
+          i-ph:warning-circle-duotone class="mr-1 inline-block translate-y-0.5 text-red-500"
+        />
+        <div
+          v-else-if="state === 'done'"
+          i-ph:check-circle-duotone class="mr-1 inline-block translate-y-0.5 text-emerald-500"
+        />
+        <div
+          v-else
+          i-solar:sledgehammer-bold-duotone class="mr-1 inline-block translate-y-1 op-50"
+        />
+        <code>{{ toolName }}</code>
+        <span v-if="state === 'error' && resultText" class="ml-2 text-xs text-red-500 op-80">
+          (failed)
+        </span>
+      </button>
+    </template>
+    <div
+      :class="[
+        'rounded-md p-2 w-full',
+        'bg-neutral-100/80 text-sm text-neutral-800 dark:bg-neutral-900/80 dark:text-neutral-200',
+      ]"
+    >
+      <template v-if="resultError">
+        <ContainerError
+          :error="resultError"
+          :include-stack="false"
+          :show-feedback-button="false"
+          height-preset="auto"
+        />
+        <div
+          :class="[
+            'mt-2 whitespace-pre-wrap break-words font-mono',
+          ]"
+        >
+          {{ formattedArgs }}
+        </div>
+      </template>
+      <template v-else-if="isTextJournalCreate">
+        <div class="mb-2 flex items-center gap-2">
+          <div class="i-solar:notebook-bookmark-bold-duotone text-base text-emerald-500" />
+          <div class="rounded-full bg-emerald-500/12 px-2.5 py-1 text-xs text-emerald-700 dark:text-emerald-300">
+            Saved to long-term memory
+          </div>
+        </div>
+        <MarkdownRenderer :content="textJournalMarkdown" />
+      </template>
+      <template v-else-if="isImageJournalCreate">
+        <div class="mb-2 flex items-center gap-2">
+          <div :class="[imageStatusIconClass, 'text-base']" />
+          <div
+            :class="[
+              'rounded-full px-2.5 py-1 text-xs',
+              imageStatusBadgeClass,
+            ]"
+          >
+            {{ imageStatusLabel }}
+          </div>
+        </div>
+        <MarkdownRenderer :content="imageJournalMarkdown" />
+
+        <div
+          v-if="imageJournalResult?.imageUrl"
+          class="mt-4 overflow-hidden border border-primary-500/20 rounded-xl shadow-lg"
+        >
+          <img
+            :src="imageJournalResult.imageUrl"
+            class="w-full cursor-pointer object-contain transition-all active:scale-[0.98] hover:ring-2 hover:ring-primary-500/50"
+            @click="openGeneratedImagePreview"
+          >
+        </div>
+      </template>
+      <div v-else class="whitespace-pre-wrap break-words font-mono">
+        {{ formattedArgs }}
+      </div>
+    </div>
+  </Collapsible>
+</template>
diff --git a/packages/stage-ui/src/components/markdown/markdown-renderer.vue b/packages/stage-ui/src/components/markdown/markdown-renderer.vue
index ffa145568..60d4b83e6 100644
--- a/packages/stage-ui/src/components/markdown/markdown-renderer.vue
+++ b/packages/stage-ui/src/components/markdown/markdown-renderer.vue
@@ -7,7 +7,7 @@ import { useMarkdown } from '../../composables/markdown'
 
 interface Props {
   content: string
-  class?: string
+  class?: string | string[]
 }
 
 const props = defineProps<Props>()
diff --git a/packages/stage-ui/src/components/scenarios/chat/components/assistant-item.vue b/packages/stage-ui/src/components/scenarios/chat/components/assistant-item.vue
index 200a522af..b156a4edf 100644
--- a/packages/stage-ui/src/components/scenarios/chat/components/assistant-item.vue
+++ b/packages/stage-ui/src/components/scenarios/chat/components/assistant-item.vue
@@ -1,5 +1,6 @@
 <script setup lang="ts">
-import type { ChatAssistantMessage, ChatHistoryItem, ChatSlices, ChatSlicesText } from '../../../../types/chat'
+import type { ChatAssistantMessage, ChatHistoryItem, ChatSlices, ChatSlicesText, ChatSlicesToolCallResult } from '../../../../types/chat'
+import type { ChatToolCallRendererRegistry } from './tool-call-renderer'
 
 import { isStageCapacitor, isStageWeb } from '@proj-airi/stage-shared'
 import { computed } from 'vue'
@@ -10,15 +11,18 @@ import ChatToolCallBlock from './tool-call-block.vue'
 import { MarkdownRenderer } from '../../../markdown'
 import { getChatHistoryItemCopyText } from '../utils'
 import { ChatActionMenu } from './action-menu'
+import { createToolCallResultLookup, resolveToolCallBlockState } from './tool-call-results'
 
 const props = withDefaults(defineProps<{
   message: ChatAssistantMessage
   label: string
   showPlaceholder?: boolean
   variant?: 'desktop' | 'mobile'
+  toolCallRenderers?: ChatToolCallRendererRegistry
 }>(), {
   showPlaceholder: false,
   variant: 'desktop',
+  toolCallRenderers: () => ({}),
 })
 
 const emit = defineEmits<{
@@ -44,6 +48,30 @@ const resolvedSlices = computed<ChatSlices[]>(() => {
   return []
 })
 
+const toolResultById = computed(() => {
+  return createToolCallResultLookup(resolvedSlices.value, props.message.tool_results)
+})
+
+function getToolCallResult(slice: ChatSlices): ChatSlicesToolCallResult | undefined {
+  if (slice.type !== 'tool-call') {
+    return undefined
+  }
+
+  return toolResultById.value.get(slice.toolCall.toolCallId)
+}
+
+function getToolCallState(slice: ChatSlices): 'executing' | 'done' | 'error' {
+  return resolveToolCallBlockState(getToolCallResult(slice))
+}
+
+function getToolCallRenderer(slice: ChatSlices) {
+  if (slice.type !== 'tool-call') {
+    return ChatToolCallBlock
+  }
+
+  return props.toolCallRenderers[slice.toolCall.toolName] ?? ChatToolCallBlock
+}
+
 const showLoader = computed(() => props.showPlaceholder && resolvedSlices.value.length === 0)
 const containerClass = computed(() => props.variant === 'mobile' ? 'mr-0' : 'mr-12')
 const boxClasses = computed(() => [
@@ -64,22 +92,29 @@ const copyText = computed(() => getChatHistoryItemCopyText(props.message as Chat
         <div
           :ref="setMeasuredElement"
           flex="~ col" shadow="sm primary-200/50 dark:none"
-          min-w-20 rounded-xl h="unset <sm:fit"
+          min-w-20 gap-2 rounded-xl h="unset <sm:fit"
           :class="[
             boxClasses,
             (isStageWeb() || isStageCapacitor()) && props.variant === 'mobile' ? 'select-none sm:select-auto' : '',
           ]"
         >
-          <div>
-            <span text-sm text="black/60 dark:white/65" font-normal class="inline <sm:hidden">{{ label }}</span>
+          <ChatResponsePart
+            v-if="message.categorization"
+            :message="message"
+            :variant="variant"
+          />
+          <div class="<sm:hidden">
+            <span text-sm text="black/60 dark:white/65" font-normal>{{ label }}</span>
           </div>
-          <div v-if="resolvedSlices.length > 0" class="break-words" text="primary-700 dark:primary-100">
+          <div v-if="resolvedSlices.length > 0" class="flex flex-col gap-2 break-words" text="primary-700 dark:primary-100">
             <template v-for="(slice, sliceIndex) in resolvedSlices" :key="sliceIndex">
-              <ChatToolCallBlock
+              <component
+                :is="getToolCallRenderer(slice)"
                 v-if="slice.type === 'tool-call'"
                 :tool-name="slice.toolCall.toolName"
                 :args="slice.toolCall.args"
-                class="mb-2"
+                :state="getToolCallState(slice)"
+                :result="getToolCallResult(slice)?.result"
               />
               <template v-else-if="slice.type === 'tool-call-result'" />
               <template v-else-if="slice.type === 'text'">
@@ -88,12 +123,6 @@ const copyText = computed(() => getChatHistoryItemCopyText(props.message as Chat
             </template>
           </div>
           <div v-else-if="showLoader" i-eos-icons:three-dots-loading />
-
-          <ChatResponsePart
-            v-if="message.categorization"
-            :message="message"
-            :variant="variant"
-          />
         </div>
       </template>
     </ChatActionMenu>
diff --git a/packages/stage-ui/src/components/scenarios/chat/components/history.story.vue b/packages/stage-ui/src/components/scenarios/chat/components/history.story.vue
index 85c6ced7a..eba33141a 100644
--- a/packages/stage-ui/src/components/scenarios/chat/components/history.story.vue
+++ b/packages/stage-ui/src/components/scenarios/chat/components/history.story.vue
@@ -6,6 +6,96 @@ import { computed, ref } from 'vue'
 import ChatScrollVisualizer from '../composables/use-element-scroll-visualize.vue'
 import ChatHistory from './history.vue'
 
+const comprehensiveMessages = ref<ChatHistoryItem[]>([
+  {
+    role: 'user',
+    content: 'Plan a compact release update. Check the task list, inspect the weather for launch timing, and explain what changed.',
+  },
+  {
+    role: 'assistant',
+    content: '',
+    slices: [
+      {
+        type: 'text',
+        text: 'I will collect the operational context first, then summarize the release status in a short update.',
+      },
+      {
+        type: 'tool-call',
+        toolCall: {
+          toolName: 'fetch_tasks',
+          args: JSON.stringify({ project: 'stage-ui', status: ['todo', 'in_progress'], limit: 4 }),
+          toolCallId: 'normal-fetch-tasks',
+          toolCallType: 'function',
+        },
+      },
+      {
+        type: 'tool-call',
+        toolCall: {
+          toolName: 'weather',
+          args: JSON.stringify({ location: 'Tokyo', date: 'today' }),
+          toolCallId: 'normal-weather',
+          toolCallType: 'function',
+        },
+      },
+      {
+        type: 'tool-call-result',
+        id: 'normal-weather',
+        result: 'Tokyo is clear with light wind. No weather risk for the launch window.',
+      },
+      {
+        type: 'tool-call',
+        toolCall: {
+          toolName: 'deploy_preview',
+          args: JSON.stringify({ branch: 'release/chat-history-states', environment: 'preview' }),
+          toolCallId: 'normal-deploy-preview',
+          toolCallType: 'function',
+        },
+      },
+      {
+        type: 'tool-call-result',
+        id: 'normal-deploy-preview',
+        isError: true,
+        result: 'Preview deployment failed: missing VITE_PUBLIC_STAGE_API_URL.',
+      },
+      {
+        type: 'text',
+        text: [
+          'Here is the release update:',
+          '',
+          '- Task scan is still running, so I will keep that status visible.',
+          '- Weather check succeeded; the launch window has no external timing concern.',
+          '- Preview deploy failed because one environment variable is missing.',
+        ].join('\n'),
+      },
+      {
+        type: 'text',
+        text: 'Next step: add `VITE_PUBLIC_STAGE_API_URL` to the preview environment, then rerun the deploy.',
+      },
+    ],
+    tool_results: [],
+    categorization: {
+      speech: 'Here is the release update. Task scan succeeded, weather is clear, and preview deploy needs one missing environment variable.',
+      reasoning: [
+        'The user asked for a compact release update, so I should keep the final answer concise.',
+        '',
+        'I need to distinguish successful tool output from the failed preview deployment. The deploy error is actionable because it names the missing environment variable.',
+      ].join('\n'),
+    },
+  },
+  {
+    role: 'assistant',
+    content: [
+      { type: 'text', text: 'This assistant message has no `slices`, so the renderer falls back to the text part from array content.' },
+    ],
+    slices: [],
+    tool_results: [],
+  },
+  {
+    role: 'error',
+    content: 'Provider stream aborted after the tool results were rendered. Retry from the previous user message if the final answer is incomplete.',
+  },
+])
+
 const markdownMessages = ref<ChatHistoryItem[]>([
   {
     role: 'user',
@@ -93,6 +183,65 @@ const toolHeavyMessages = computed<ChatHistoryItem[]>(() => [
   },
 ])
 
+const hybridToolFailureMessages = ref<ChatHistoryItem[]>([
+  {
+    role: 'user',
+    content: 'Start a chess game for me, then recover if the setup fails.',
+  },
+  {
+    role: 'assistant',
+    content: '',
+    slices: [
+      {
+        type: 'tool-call',
+        toolCall: {
+          toolName: 'play_chess',
+          args: JSON.stringify({ mode: 'focus' }),
+          toolCallId: 'hybrid-play-chess-focus',
+          toolCallType: 'function',
+        },
+      },
+      {
+        type: 'text',
+        text: 'I found the chess widget and brought it forward. I will try to bootstrap a fresh L1 match now.',
+      },
+      {
+        type: 'tool-call',
+        toolCall: {
+          toolName: 'play_chess',
+          args: JSON.stringify({
+            difficultyLevel: 'L1',
+            difficultyMode: 'manual',
+            fen: null,
+            mode: 'new',
+            notes: 'L1 game started; assistant plays White and will move first.',
+            opening: null,
+            pgn: null,
+            side: 'white',
+          }),
+          toolCallId: 'hybrid-play-chess-new-failed',
+          toolCallType: 'function',
+        },
+      },
+      {
+        type: 'text',
+        text: 'That setup attempt failed because focus mode rejected mutation inputs. I will keep the board open and retry with a clean new-game payload next.',
+      },
+    ],
+    tool_results: [
+      {
+        id: 'hybrid-play-chess-focus',
+        result: 'Focused the existing chess gamelet.',
+      },
+      {
+        id: 'hybrid-play-chess-new-failed',
+        isError: true,
+        result: 'Focus mode does not accept game-state mutation inputs.',
+      },
+    ],
+  },
+])
+
 const errorMessages = ref<ChatHistoryItem[]>([
   {
     role: 'user',
@@ -134,6 +283,15 @@ const streamingMessage = ref<ChatAssistantMessage>({
       <ThemeColorsHueControl />
     </template>
 
+    <Variant
+      id="all-normal-message-parts"
+      title="All Normal Message Parts"
+    >
+      <div class="font-cute">
+        <ChatHistory :messages="comprehensiveMessages" />
+      </div>
+    </Variant>
+
     <Variant
       id="with-tools-desktop"
       title="With Tools"
@@ -182,6 +340,15 @@ const streamingMessage = ref<ChatAssistantMessage>({
       </div>
     </Variant>
 
+    <Variant
+      id="hybrid-tool-failure"
+      title="Hybrid Tool Failure"
+    >
+      <div class="font-cute">
+        <ChatHistory :messages="hybridToolFailureMessages" />
+      </div>
+    </Variant>
+
     <Variant
       id="streaming"
       title="Streaming"
diff --git a/packages/stage-ui/src/components/scenarios/chat/components/history.vue b/packages/stage-ui/src/components/scenarios/chat/components/history.vue
index 34262b867..98ee4d6cb 100644
--- a/packages/stage-ui/src/components/scenarios/chat/components/history.vue
+++ b/packages/stage-ui/src/components/scenarios/chat/components/history.vue
@@ -1,5 +1,6 @@
 <script setup lang="ts">
 import type { ChatAssistantMessage, ChatHistoryItem, ContextMessage } from '../../../../types/chat'
+import type { ChatToolCallRendererRegistry } from './tool-call-renderer'
 
 import { computed, provide, ref } from 'vue'
 import { useI18n } from 'vue-i18n'
@@ -21,9 +22,11 @@ const props = withDefaults(defineProps<{
   errorLabel?: string
   retryLabel?: string
   variant?: 'desktop' | 'mobile'
+  toolCallRenderers?: ChatToolCallRendererRegistry
 }>(), {
   sending: false,
   variant: 'desktop',
+  toolCallRenderers: () => ({}),
 })
 
 const emit = defineEmits<{
@@ -125,6 +128,7 @@ function emitRetryMessage(message: ChatHistoryItem, index: number) {
           :label="labels.assistant"
           :show-placeholder="shouldShowPlaceholder(message) && showStreamingPlaceholder"
           :variant="variant"
+          :tool-call-renderers="toolCallRenderers"
           @copy="emitCopyMessage(message, index)"
           @delete="emitDeleteMessage(message, index)"
         />
diff --git a/packages/stage-ui/src/components/scenarios/chat/components/response-part.vue b/packages/stage-ui/src/components/scenarios/chat/components/response-part.vue
index 1aa7c6cf8..a5d809fc8 100644
--- a/packages/stage-ui/src/components/scenarios/chat/components/response-part.vue
+++ b/packages/stage-ui/src/components/scenarios/chat/components/response-part.vue
@@ -1,9 +1,8 @@
 <script setup lang="ts">
 import type { ChatAssistantMessage } from '../../../../types/chat'
 
-import { Collapsible } from '@proj-airi/ui'
+import { Truncatable } from '@proj-airi/ui'
 import { computed } from 'vue'
-import { useI18n } from 'vue-i18n'
 
 import { MarkdownRenderer } from '../../../markdown'
 
@@ -12,9 +11,8 @@ const props = defineProps<{
   variant?: 'desktop' | 'mobile'
 }>()
 
-const { t } = useI18n()
-
-const hasReasoning = computed(() => !!props.message.categorization?.reasoning?.trim())
+const reasoningContent = computed(() => props.message.categorization?.reasoning?.trim() ?? '')
+const hasReasoning = computed(() => reasoningContent.value.length > 0)
 
 const containerClasses = computed(() => [
   'mt-2',
@@ -24,33 +22,12 @@ const containerClasses = computed(() => [
 
 <template>
   <div v-if="hasReasoning" :class="containerClasses" flex="~ col" gap-1>
-    <Collapsible :default="false">
-      <template #trigger="slotProps">
-        <button
-          class="w-full flex items-center justify-between rounded-lg bg-neutral-100/50 px-2 py-1 text-xs text-neutral-600 outline-none transition-all duration-200 dark:bg-neutral-800/50 hover:bg-neutral-200/50 dark:text-neutral-400 dark:hover:bg-neutral-700/50"
-          @click="slotProps.setVisible(!slotProps.visible)"
-        >
-          <div flex="~ items-center" gap-1.5>
-            <div i-solar:lightbulb-bolt-bold-duotone size-3.5 text-amber-500 dark:text-amber-400 />
-            <span font-medium>{{ t('stage.chat.reasoning') }}</span>
-          </div>
-          <div
-            i-solar:alt-arrow-down-linear
-            size-3
-            transition="transform duration-200"
-            :class="{ 'rotate-180': slotProps.visible }"
-          />
-        </button>
-      </template>
-      <div
-        class="mt-1 border border-neutral-200 rounded-md bg-neutral-50/80 px-2 py-1.5 dark:border-neutral-700 dark:bg-neutral-900/80"
-      >
-        <MarkdownRenderer
-          :content="message.categorization?.reasoning ?? ''"
-          class="break-words"
-          text="xs neutral-700 dark:neutral-300"
-        />
-      </div>
-    </Collapsible>
+    <Truncatable :line-clamp="1">
+      <MarkdownRenderer
+        :content="reasoningContent"
+        :class="['break-words']"
+        text="sm neutral-700/50 dark:neutral-300/50"
+      />
+    </Truncatable>
   </div>
 </template>
diff --git a/packages/stage-ui/src/components/scenarios/chat/components/tool-call-block.vue b/packages/stage-ui/src/components/scenarios/chat/components/tool-call-block.vue
index ed411fc41..5bbb058b0 100644
--- a/packages/stage-ui/src/components/scenarios/chat/components/tool-call-block.vue
+++ b/packages/stage-ui/src/components/scenarios/chat/components/tool-call-block.vue
@@ -1,92 +1,17 @@
 <script setup lang="ts">
-import { MarkdownRenderer } from '@proj-airi/stage-ui/components'
-import { useJournalPreviewStore } from '@proj-airi/stage-ui/stores/journal-preview'
-import { Collapsible } from '@proj-airi/ui'
+import { Collapsible, ContainerError } from '@proj-airi/ui'
 import { computed } from 'vue'
 
+import { createToolResultError } from './tool-call-display'
+
 const props = defineProps<{
   toolName: string
   args: string
   state?: 'executing' | 'done' | 'error'
-  result?: any
+  result?: unknown
 }>()
 
-const journalPreviewStore = useJournalPreviewStore()
-const { openImagePreview } = journalPreviewStore
-
-interface TextJournalArgs {
-  action?: string
-  title?: string
-  content?: string
-}
-
-interface ImageJournalArgs {
-  action?: string
-  prompt?: string
-  title?: string
-  mode?: 'inline' | 'widget' | 'bg'
-}
-
-const parsedArgs = computed<TextJournalArgs | null>(() => {
-  try {
-    return JSON.parse(props.args) as TextJournalArgs
-  }
-  catch {
-    return null
-  }
-})
-
-const isTextJournalCreate = computed(() => {
-  return props.toolName === 'text_journal'
-    && parsedArgs.value?.action === 'create'
-    && !!parsedArgs.value?.content?.trim()
-})
-
-const isImageJournalCreate = computed(() => {
-  return props.toolName === 'image_journal'
-    && parsedArgs.value?.action === 'create'
-    && !!(parsedArgs.value as ImageJournalArgs)?.prompt?.trim()
-})
-
-const textJournalMarkdown = computed(() => {
-  if (!isTextJournalCreate.value)
-    return ''
-
-  const title = parsedArgs.value?.title?.trim() || 'Journal Entry'
-  const content = parsedArgs.value?.content?.trim() || ''
-  return `# ${title}\n\n${content}`
-})
-
-const imageJournalMarkdown = computed(() => {
-  if (!isImageJournalCreate.value)
-    return ''
-
-  const args = parsedArgs.value as ImageJournalArgs
-  const title = args?.title?.trim() || 'Untitled Image'
-  const prompt = args?.prompt?.trim() || ''
-  const mode = args?.mode || 'inline'
-
-  let footer = ''
-  if (mode === 'bg')
-    footer = '\n\n> **Scene Shift**: Setting this as the active background...'
-  else if (mode === 'widget')
-    footer = '\n\n> **Canvas Created**: Spawning an artistry widget for you...'
-  else
-    footer = '\n\n> **Sharing**: Sending a quick sketch to our chat history...'
-
-  return `### ${title}\n\n*${prompt}*${footer}`
-})
-
-const imageJournalResult = computed(() => {
-  if (props.toolName !== 'image_journal' || !props.result)
-    return null
-  try {
-    return typeof props.result === 'string' ? JSON.parse(props.result) : props.result
-  }
-  catch {
-    return null
-  }
-})
+const resultError = computed(() => props.state === 'error' ? createToolResultError(props.result) : undefined)
 
 const formattedArgs = computed(() => {
   try {
@@ -102,7 +27,7 @@ const formattedArgs = computed(() => {
 <template>
   <Collapsible
     :class="[
-      'bg-primary-100/40 dark:bg-primary-900/60 rounded-lg px-2 pb-2 pt-2',
+      'bg-primary-100/40 dark:bg-primary-900/60 rounded-lg px-1 pb-1 pt-1',
       'flex flex-col gap-2 items-start',
     ]"
   >
@@ -110,29 +35,27 @@ const formattedArgs = computed(() => {
       <button
         :class="[
           'w-full text-start',
+          'inline-flex items-center',
         ]"
         @click="setVisible(!visible)"
       >
         <div
           v-if="state === 'executing'"
-          i-eos-icons:loading class="mr-1 inline-block translate-y-0.5 op-50"
+          i-eos-icons:loading class="mr-1 inline-block op-50"
         />
         <div
           v-else-if="state === 'error'"
-          i-ph:warning-circle-duotone class="mr-1 inline-block translate-y-0.5 text-red-500"
+          i-solar:danger-circle-bold-duotone class="mr-1 inline-block text-red-500"
         />
         <div
           v-else-if="state === 'done'"
-          i-ph:check-circle-duotone class="mr-1 inline-block translate-y-0.5 text-emerald-500"
+          i-solar:check-circle-bold-duotone class="mr-1 inline-block text-emerald-500"
         />
         <div
           v-else
           i-solar:sledgehammer-bold-duotone class="mr-1 inline-block translate-y-1 op-50"
         />
-        <code>{{ toolName }}</code>
-        <span v-if="state === 'error' && result" class="ml-2 text-xs text-red-500 op-80">
-          ({{ result }})
-        </span>
+        <code class="text-xs">{{ toolName }}</code>
       </button>
     </template>
     <div
@@ -141,38 +64,19 @@ const formattedArgs = computed(() => {
         'bg-neutral-100/80 text-sm text-neutral-800 dark:bg-neutral-900/80 dark:text-neutral-200',
       ]"
     >
-      <template v-if="isTextJournalCreate">
-        <div class="mb-2 flex items-center gap-2">
-          <div class="i-solar:notebook-bookmark-bold-duotone text-base text-emerald-500" />
-          <div class="rounded-full bg-emerald-500/12 px-2.5 py-1 text-xs text-emerald-700 dark:text-emerald-300">
-            Saved to long-term memory
-          </div>
-        </div>
-        <MarkdownRenderer :content="textJournalMarkdown" />
-      </template>
-      <template v-else-if="isImageJournalCreate">
-        <div class="mb-2 flex items-center gap-2">
-          <div :class="[(parsedArgs as ImageJournalArgs)?.mode === 'bg' ? 'i-solar:gallery-wide-bold-duotone text-emerald-500' : 'i-solar:camera-bold-duotone text-violet-500']" class="text-base" />
-          <div
-            class="rounded-full px-2.5 py-1 text-xs"
-            :class="[
-              (parsedArgs as ImageJournalArgs)?.mode === 'bg'
-                ? 'bg-emerald-500/12 text-emerald-700 dark:text-emerald-300'
-                : 'bg-violet-500/12 text-violet-700 dark:text-violet-300',
-            ]"
-          >
-            {{ (parsedArgs as ImageJournalArgs)?.mode === 'bg' ? 'Updating Scene' : 'Generating image' }}
-          </div>
-        </div>
-        <MarkdownRenderer :content="imageJournalMarkdown" />
-
-        <!-- Result Rendering (for inline mode) -->
-        <div v-if="imageJournalResult?.imageUrl" class="mt-4 overflow-hidden border border-primary-500/20 rounded-xl shadow-lg">
-          <img
-            :src="imageJournalResult.imageUrl"
-            class="w-full cursor-pointer object-contain transition-all active:scale-[0.98] hover:ring-2 hover:ring-primary-500/50"
-            @click="openImagePreview({ title: (parsedArgs as ImageJournalArgs)?.title || 'Generated Image', url: imageJournalResult.imageUrl })"
-          >
+      <template v-if="resultError">
+        <ContainerError
+          :error="resultError"
+          :include-stack="false"
+          :show-feedback-button="false"
+          height-preset="auto"
+        />
+        <div
+          :class="[
+            'mt-2 whitespace-pre-wrap break-words font-mono',
+          ]"
+        >
+          {{ formattedArgs }}
         </div>
       </template>
       <div v-else class="whitespace-pre-wrap break-words font-mono">
diff --git a/packages/stage-ui/src/components/scenarios/chat/components/tool-call-display.test.ts b/packages/stage-ui/src/components/scenarios/chat/components/tool-call-display.test.ts
new file mode 100644
index 000000000..0a7fb6642
--- /dev/null
+++ b/packages/stage-ui/src/components/scenarios/chat/components/tool-call-display.test.ts
@@ -0,0 +1,30 @@
+import { describe, expect, it } from 'vitest'
+
+import { createToolResultError, normalizeToolResultText } from './tool-call-display'
+
+describe('tool call display helpers', () => {
+  /**
+   * @example
+   * expect(normalizeToolResultText({ ok: true })).toContain('"ok": true')
+   */
+  it('normalizes structured tool results into copyable text', () => {
+    const text = normalizeToolResultText({
+      ok: true,
+      mode: 'focus',
+    })
+
+    expect(text).toContain('"ok": true')
+    expect(text).toContain('"mode": "focus"')
+  })
+
+  /**
+   * @example
+   * expect(createToolResultError('Tool failed')?.message).toBe('Tool failed')
+   */
+  it('creates an Error wrapper for failed tool results', () => {
+    const error = createToolResultError('Tool call error for "play_chess": Focus mode does not accept game-state mutation inputs.')
+
+    expect(error).toBeInstanceOf(Error)
+    expect(error?.message).toContain('Focus mode does not accept game-state mutation inputs.')
+  })
+})
diff --git a/packages/stage-ui/src/components/scenarios/chat/components/tool-call-display.ts b/packages/stage-ui/src/components/scenarios/chat/components/tool-call-display.ts
new file mode 100644
index 000000000..05b41ca8c
--- /dev/null
+++ b/packages/stage-ui/src/components/scenarios/chat/components/tool-call-display.ts
@@ -0,0 +1,48 @@
+/**
+ * Normalizes a tool result into readable text for compact chat UI.
+ *
+ * Before:
+ * - { ok: true, mode: "focus" }
+ * - "Tool call error for \"play_chess\": failed"
+ *
+ * After:
+ * - "{\n  \"ok\": true,\n  \"mode\": \"focus\"\n}"
+ * - "Tool call error for \"play_chess\": failed"
+ */
+export function normalizeToolResultText(result: unknown): string {
+  if (result == null) {
+    return ''
+  }
+
+  if (typeof result === 'string') {
+    return result.trim()
+  }
+
+  try {
+    return JSON.stringify(result, null, 2).trim()
+  }
+  catch {
+    return String(result).trim()
+  }
+}
+
+/**
+ * Creates a displayable `Error` from a failed tool result.
+ *
+ * Use when:
+ * - A tool call block needs to reuse the shared copyable error panel
+ *
+ * Expects:
+ * - Tool failures may arrive as strings or structured values
+ *
+ * Returns:
+ * - `Error` when there is readable text, otherwise `undefined`
+ */
+export function createToolResultError(result: unknown): Error | undefined {
+  const message = normalizeToolResultText(result)
+  if (!message) {
+    return undefined
+  }
+
+  return new Error(message)
+}
diff --git a/packages/stage-ui/src/components/scenarios/chat/components/tool-call-renderer.ts b/packages/stage-ui/src/components/scenarios/chat/components/tool-call-renderer.ts
new file mode 100644
index 000000000..481c1c986
--- /dev/null
+++ b/packages/stage-ui/src/components/scenarios/chat/components/tool-call-renderer.ts
@@ -0,0 +1,27 @@
+import type { Component } from 'vue'
+
+/**
+ * Props passed to a tool-call renderer component.
+ *
+ * Use when:
+ * - A runtime registers a custom renderer for a tool name
+ * - A generic chat surface needs to forward tool-call render data without owning runtime state
+ *
+ * Expects:
+ * - `args` is the raw serialized tool-call argument payload
+ * - `result` is the latest matching tool-call result when available
+ *
+ * Returns:
+ * - A prop contract that custom runtime renderers can implement
+ */
+export interface ChatToolCallRendererProps {
+  toolName: string
+  args: string
+  state?: 'executing' | 'done' | 'error'
+  result?: unknown
+}
+
+/**
+ * Maps tool names to custom renderer components.
+ */
+export type ChatToolCallRendererRegistry = Partial<Record<string, Component>>
diff --git a/packages/stage-ui/src/components/scenarios/chat/components/tool-call-results.test.ts b/packages/stage-ui/src/components/scenarios/chat/components/tool-call-results.test.ts
new file mode 100644
index 000000000..8ce8b5491
--- /dev/null
+++ b/packages/stage-ui/src/components/scenarios/chat/components/tool-call-results.test.ts
@@ -0,0 +1,84 @@
+import type { ChatAssistantMessage } from '../../../../types/chat'
+
+import { describe, expect, it } from 'vitest'
+
+import { createToolCallResultLookup, resolveToolCallBlockState } from './tool-call-results'
+
+describe('tool call result lookup', () => {
+  /**
+   * @example
+   * expect(resolveToolCallBlockState(undefined)).toBe('executing')
+   */
+  it('marks a tool call without a result as executing', () => {
+    expect(resolveToolCallBlockState(undefined)).toBe('executing')
+  })
+
+  /**
+   * @example
+   * expect(resolveToolCallBlockState(result)).toBe('done')
+   */
+  it('marks a successful tool result as done', () => {
+    const message: ChatAssistantMessage = {
+      role: 'assistant',
+      content: '',
+      slices: [
+        {
+          type: 'tool-call',
+          toolCall: {
+            toolCallId: 'call-weather',
+            toolCallType: 'function',
+            toolName: 'weather',
+            args: JSON.stringify({ location: 'Tokyo' }),
+          },
+        },
+        {
+          type: 'tool-call-result',
+          id: 'call-weather',
+          result: 'Tokyo is clear with light wind.',
+        },
+      ],
+      tool_results: [],
+    }
+
+    const lookup = createToolCallResultLookup(message.slices, message.tool_results)
+    const result = lookup.get('call-weather')
+
+    expect(result?.result).toBe('Tokyo is clear with light wind.')
+    expect(resolveToolCallBlockState(result)).toBe('done')
+  })
+
+  /**
+   * @example
+   * expect(resolveToolCallBlockState(result)).toBe('error')
+   */
+  it('pairs a failed tool result with its tool call id', () => {
+    const message: ChatAssistantMessage = {
+      role: 'assistant',
+      content: '',
+      slices: [
+        {
+          type: 'tool-call',
+          toolCall: {
+            toolCallId: 'call-play-chess',
+            toolCallType: 'function',
+            toolName: 'play_chess',
+            args: JSON.stringify({ mode: 'new', side: 'white' }),
+          },
+        },
+      ],
+      tool_results: [
+        {
+          id: 'call-play-chess',
+          isError: true,
+          result: 'Focus mode does not accept game-state mutation inputs.',
+        },
+      ],
+    }
+
+    const lookup = createToolCallResultLookup(message.slices, message.tool_results)
+    const result = lookup.get('call-play-chess')
+
+    expect(result?.result).toBe('Focus mode does not accept game-state mutation inputs.')
+    expect(resolveToolCallBlockState(result)).toBe('error')
+  })
+})
diff --git a/packages/stage-ui/src/components/scenarios/chat/components/tool-call-results.ts b/packages/stage-ui/src/components/scenarios/chat/components/tool-call-results.ts
new file mode 100644
index 000000000..dce7ce43a
--- /dev/null
+++ b/packages/stage-ui/src/components/scenarios/chat/components/tool-call-results.ts
@@ -0,0 +1,57 @@
+import type { ChatAssistantMessage, ChatSlices, ChatSlicesToolCallResult } from '../../../../types/chat'
+
+/**
+ * Creates a lookup from tool-call id to its latest result slice.
+ *
+ * Use when:
+ * - Rendering assistant messages with separate `tool-call` and `tool-call-result` data
+ * - Streaming messages store tool results on `tool_results` instead of inline slices
+ *
+ * Expects:
+ * - Tool call ids use `toolCall.toolCallId`
+ * - Tool result ids use `id`
+ *
+ * Returns:
+ * - A map keyed by tool call id, preferring inline result slices over stored results
+ */
+export function createToolCallResultLookup(
+  slices: ChatSlices[],
+  toolResults: ChatAssistantMessage['tool_results'] = [],
+): Map<string, ChatSlicesToolCallResult> {
+  const resultMap = new Map<string, ChatSlicesToolCallResult>()
+
+  for (const result of toolResults) {
+    resultMap.set(result.id, {
+      type: 'tool-call-result',
+      ...result,
+    })
+  }
+
+  for (const slice of slices) {
+    if (slice.type === 'tool-call-result') {
+      resultMap.set(slice.id, slice)
+    }
+  }
+
+  return resultMap
+}
+
+/**
+ * Resolves the visual state for a tool call block from its result.
+ *
+ * Use when:
+ * - Tool call UI needs to show success or failure without replacing the assistant message
+ *
+ * Expects:
+ * - Missing result means the call is still running
+ *
+ * Returns:
+ * - `executing` for missing results, `error` for failed results, or `done` for successful results
+ */
+export function resolveToolCallBlockState(result: ChatSlicesToolCallResult | undefined): 'executing' | 'done' | 'error' {
+  if (!result) {
+    return 'executing'
+  }
+
+  return result.isError ? 'error' : 'done'
+}
diff --git a/packages/stage-ui/src/components/scenarios/chat/index.ts b/packages/stage-ui/src/components/scenarios/chat/index.ts
index 43250f1a9..892f15445 100644
--- a/packages/stage-ui/src/components/scenarios/chat/index.ts
+++ b/packages/stage-ui/src/components/scenarios/chat/index.ts
@@ -2,5 +2,7 @@ export { ChatActionMenu } from './components/action-menu'
 export { default as ChatAssistantItem } from './components/assistant-item.vue'
 export { default as ChatErrorItem } from './components/error-item.vue'
 export { default as ChatHistory } from './components/history.vue'
+export { createToolResultError, normalizeToolResultText } from './components/tool-call-display'
+export type { ChatToolCallRendererProps, ChatToolCallRendererRegistry } from './components/tool-call-renderer'
 export { default as ChatUserItem } from './components/user-item.vue'
 export { default as JournalPreviewModal } from './JournalPreviewModal.vue'
diff --git a/packages/ui/src/components/misc/container-error.vue b/packages/ui/src/components/misc/container-error.vue
index 1f6427d88..cac07dedf 100644
--- a/packages/ui/src/components/misc/container-error.vue
+++ b/packages/ui/src/components/misc/container-error.vue
@@ -157,11 +157,10 @@ async function copyContent() {
 <template>
   <div
     :class="[
-      'relative w-full rounded-xl border-2 border-red-200/70 bg-red-50/60 backdrop-blur-md p-1',
-      'dark:border-red-900/50 dark:bg-red-950/25',
+      'relative w-full rounded-lg bg-red-50/60 dark:bg-red-950/25 backdrop-blur-md p-1',
     ]"
   >
-    <div :class="['absolute right-4 -translate-x-full top-2 z-10']">
+    <div :class="['absolute right-2 -translate-x-full top-2 z-10']">
       <Button
         v-if="showCopyButton"
         size="sm"
@@ -172,9 +171,7 @@ async function copyContent() {
         :aria-label="copied ? copiedButtonLabel : copyButtonLabel"
         @click="copyContent"
       />
-    </div>
 
-    <div :class="['absolute right-2 top-2 z-10']">
       <Button
         v-if="showFeedbackButton"
         size="sm"
@@ -191,13 +188,12 @@ async function copyContent() {
       type="auto"
       :class="[
         'relative w-full overflow-hidden rounded-xl',
-        'bg-neutral-50/80 dark:bg-neutral-950/80',
         ...heightPresetClasses[heightPreset],
       ]"
     >
       <ScrollAreaViewport :class="['h-full w-full']">
         <div :class="['flex flex-col gap-2 p-3 text-xs']">
-          <div v-if="resolvedErrorName || resolvedMessage" :class="['font-mono font-semibold text-red-700 leading-relaxed dark:text-red-300']">
+          <div v-if="resolvedErrorName || resolvedMessage" :class="['font-mono text-red-700 leading-relaxed dark:text-red-300']">
             {{ resolvedErrorName || 'Error' }}
             <span v-if="resolvedMessage">
               : {{ resolvedMessage }}