feat: add sendToolResult function for MCP format handling

- Introduced global.sendToolResult function to send tool results in MCP format.
- Supports both string content and structured CallToolResult objects.
- Updated type definitions to include sendToolResult with detailed documentation and examples.

Author: johnlindquist

src/api/kit.ts

@@ -40,7 +40,7 @@ import { getScripts, getScriptFromString, getUserJson, getTimestamps, type Stamp
 
 import { default as stripAnsi } from 'strip-ansi'
 
-import type { Kenv } from '../types/kit'
+import type { CallToolResult, Kenv } from '../types/kit'
 import type { Fields as TraceFields } from 'chrome-trace-event'
 import dotenv from 'dotenv'
 import type { kenvEnv } from '../types/env'
@@ -318,6 +318,35 @@ global.sendResponse = (body: any, headers: Record<string, string> = {}) => {
   return global.sendWait(Channel.RESPONSE, response)
 }
 
+global.sendToolResult = (content: string | CallToolResult) => {
+  // Format content according to MCP tool result specification
+  let toolResult: CallToolResult;
+
+  if (typeof content === 'string') {
+    // If content is a string, wrap it in the MCP format
+    toolResult = {
+      content: [
+        {
+          type: 'text',
+          text: content
+        }
+      ]
+    };
+  } else {
+    // Content is already in MCP format
+    toolResult = content;
+  }
+
+  // Send the tool result using the same RESPONSE channel
+  return global.sendWait(Channel.RESPONSE, {
+    body: toolResult,
+    statusCode: 200,
+    headers: {
+      'Content-Type': 'application/json'
+    }
+  });
+}
+
 // Import and export params function
 import { params } from './params.js'
 global.params = params

src/types/kitapp.d.ts

@@ -19,6 +19,7 @@ import {
   type Script,
   type Shortcut
 } from './core.js'
+import type { CallToolResult } from './kit'
 import type { BrowserWindowConstructorOptions, Display, Rectangle } from './electron.js'
 
 import type { Trash } from './packages.js'
@@ -1296,6 +1297,33 @@ declare global {
   var sendWait: (channel: Channel, value?: any, timeout?: number) => Promise<any>
   var headers: Record<string, string>
   var sendResponse: (body: any, headers?: Record<string, string>) => Promise<any>
+  /**
+   * Send a tool result in MCP (Model Context Protocol) format
+   * @param content - The content to send. Can be a string (automatically formatted) or a CallToolResult object
+   * @returns Promise that resolves when the result is sent
+   * @example
+   * ```ts
+   * // Send a simple string result
+   * await sendToolResult("Hello from MCP tool!")
+   * 
+   * // Send a structured MCP result
+   * await sendToolResult({
+   *   content: [{
+   *     type: 'text',
+   *     text: 'Processed successfully'
+   *   }]
+   * })
+   * 
+   * // Send multiple content items
+   * await sendToolResult({
+   *   content: [
+   *     { type: 'text', text: 'Analysis complete.' },
+   *     { type: 'image', data: imageBase64, mimeType: 'image/png' }
+   *   ]
+   * })
+   * ```
+   */
+  var sendToolResult: (content: string | CallToolResult) => Promise<any>
   var sendWaitLong: (channel: Channel, value?: any, timeout?: number) => Promise<any>
 
   var setFocused: SetFocused