This server has significant gaps in definition quality. All three tools are explicitly registered in src/index.ts with schemas and descriptions, but the quality is inconsistent. Tool names follow verb_noun conventions (post_to_x, list_x_posts, create_x_thread), which is good. However, descriptions are minimal (16-40 chars), parameter descriptions are sparse, and critical metadata is missing. The incomplete source code (CallToolRequestSchema handler cuts off mid-execution) prevents full validation of runtime behavior. No error handling guidance is visible for LLM recovery. Output schemas are not documented. The server exposes Twitter API credentials via environment variables correctly, but parameter validation logic is incomplete.

• Add comprehensive output schemas to all three tools. For create_x_thread: return { thread_id: string, created_at: string, url: string }. For post_to_x: return { post_id: string, thread_id: string, created_at: string, url: string }. For list_x_posts: return { posts: [{ id, content, created_at, thread_id }], total: number, next_cursor?: string }. These enable downstream chaining.
• Expand tool descriptions to 100-200 chars each, explaining WHEN and WHY to use each tool. Example for list_x_posts: 'Retrieve recent posts, optionally filtered by thread. Returns up to 100 posts with pagination support. Use this to check thread history before posting or to verify posts were created.'
• Add constraints to parameters. limit: min 1, max 100, default 20. content: min 1, max 280 chars (or API limit). threadId: description should say 'Optional. Leave empty to start a new thread; provide an existing thread ID to add to a conversation. Obtain IDs from list_x_posts output.'
• Document error scenarios and LLM recovery guidance. Example: 'If content exceeds 280 chars, list_x_posts will return an error. Consider breaking into a thread. If threadId is invalid, list_x_posts will return 404, search for the thread by content using search functionality.'
• Implement pagination for list_x_posts. Add next_cursor to response; accept cursor parameter in subsequent calls. Document in description: 'Results are paginated. Use next_cursor from the response to fetch more posts. Default limit is 20; max 100.'
• Add tool annotations. Decorate post_to_x and create_x_thread with destructiveHint=true. Decorate list_x_posts with readOnlyHint=true. This signals to the LLM which tools have irreversible side effects.