diff --git a/packages/stage-ui/src/tools/mcp.ts b/packages/stage-ui/src/tools/mcp.ts
index bb5cb9a0e..151e77c60 100644
--- a/packages/stage-ui/src/tools/mcp.ts
+++ b/packages/stage-ui/src/tools/mcp.ts
@@ -10,11 +10,10 @@ const tools = [
       return await listTools()
     },
     parameters: z.object({}),
-    returns: z.object({}),
   }),
   tool({
     name: 'mcp_connect_server',
-    description: 'Connect to the MCP server',
+    description: 'Connect to the MCP server. If "success", the connection to the MCP server is successful. Otherwise, the connection fails.',
     execute: async ({ command, args }) => {
       await connectServer(command, args)
       return 'success'
@@ -23,25 +22,29 @@ const tools = [
       command: z.string().describe('The command to connect to the MCP server'),
       args: z.array(z.string()).describe('The arguments to pass to the MCP server'),
     }),
-    returns: z.string().describe('If "success", the connection to the MCP server is successful. Otherwise, the connection fails.'),
   }),
   tool({
     name: 'mcp_disconnect_server',
-    description: 'Disconnect from the MCP server',
+    description: 'Disconnect from the MCP server. If "success", the disconnection from the MCP server is successful. Otherwise, the disconnection fails.',
     execute: async () => {
       await disconnectServer()
       return 'success'
     },
     parameters: z.object({}),
-    returns: z.string().describe('If "success", the connection to the MCP server is successful. Otherwise, the connection fails.'),
   }),
   tool({
     name: 'mcp_call_tool',
-    description: 'Call a tool on the MCP server',
+    description: 'Call a tool on the MCP server. The result is a list of content and a boolean indicating whether the tool call is an error.',
     execute: async ({ name, parameters }) => {
       const parametersObject = Object.fromEntries(parameters.map(({ name, value }) => [name, value]))
       const result = await callTool(name, parametersObject)
-      return result
+      return result satisfies {
+        content: {
+          type: string
+          text: string
+        }[]
+        isError: boolean
+      }
     },
     parameters: z.object({
       name: z.string().describe('The name of the tool to call'),
@@ -50,13 +53,6 @@ const tools = [
         value: z.any().describe('The value of the parameter'),
       })).describe('The parameters to pass to the tool'),
     }),
-    returns: z.object({
-      content: z.array(z.object({
-        type: z.string().describe('The type of the content'),
-        text: z.string().describe('The text of the content'),
-      })).describe('The content of the tool call result'),
-      isError: z.boolean().describe('Whether the tool call is an error'),
-    }).describe('The result of the tool call'),
   }),
 ]