Add MCP Tool Annotations and Structured Output

[foxintheloop]

Problem

MCP tools lack metadata that helps clients understand tool behavior. The MCP spec (2025-06-18) recommends annotations and structured output.

Solution

Add to each tool definition:

• annotations with readOnlyHint, destructiveHint, idempotentHint
• title field for human-readable display names
• Catch ZodError specifically and format as user-friendly string

Annotation mapping:

• Read-only: get_tasks, get_task, get_productivity_dashboard, get_priorities
• Destructive: delete_task, delete_list, delete_goal
• Non-idempotent: all create/update tools

Files

• apps/mcp-server/src/tools/*.ts — add annotations to tool definitions
• apps/mcp-server/src/index.ts — add ZodError formatting in catch block