feat(mcp): Implement update-subtask MCP command for appending information to subtasks

mcp-server/src/tools/update-subtask.js

@@ -0,0 +1,51 @@
+/**
+ * tools/update-subtask.js
+ * Tool to append additional information to a specific subtask
+ */
+
+import { z } from "zod";
+import {
+  handleApiResult,
+  createErrorResponse
+} from "./utils.js";
+import { updateSubtaskByIdDirect } from "../core/task-master-core.js";
+
+/**
+ * Register the update-subtask tool with the MCP server
+ * @param {Object} server - FastMCP server instance
+ */
+export function registerUpdateSubtaskTool(server) {
+  server.addTool({
+    name: "update-subtask",
+    description: "Appends additional information to a specific subtask without replacing existing content",
+    parameters: z.object({
+      id: z.string().describe("ID of the subtask to update in format \"parentId.subtaskId\" (e.g., \"5.2\")"),
+      prompt: z.string().describe("Information to add to the subtask"),
+      research: z.boolean().optional().describe("Use Perplexity AI for research-backed updates"),
+      file: z.string().optional().describe("Path to the tasks file"),
+      projectRoot: z
+        .string()
+        .optional()
+        .describe(
+          "Root directory of the project (default: current working directory)"
+        ),
+    }),
+    execute: async (args, { log }) => {
+      try {
+        log.info(`Updating subtask with args: ${JSON.stringify(args)}`);
+        
+        // Call the direct function wrapper
+        const result = await updateSubtaskByIdDirect(args, log);
+        
+        // Log result
+        log.info(`${result.success ? `Successfully updated subtask with ID ${args.id}` : 'Failed to update subtask'}`);
+        
+        // Use handleApiResult to format the response
+        return handleApiResult(result, log, 'Error updating subtask');
+      } catch (error) {
+        log.error(`Error in update-subtask tool: ${error.message}`);
+        return createErrorResponse(error.message);
+      }
+    },
+  });
+}