Moodify exposes 25 Spotify-integration tools via HTTP/Streamable transport. Critical gaps: NO tool descriptions visible in source code (all 25 tools score 0 on description dimension). Input schemas are inferred from Zod validators in implementation files but NOT explicitly registered in tool definitions, cannot verify schema completeness. Tool names follow verb_noun convention (search_tracks, play_track, get_queue) which is good, but without descriptions, LLMs cannot determine when to select each tool. No error handling guidance, no output schema documentation, no parameter descriptions visible. This is a functional Spotify client but fails basic agent-tool quality standards.

• Add a 50 - 200 character description to every tool. Example for search_tracks: 'Search Spotify for tracks by name, artist, or album. Returns up to 20 results with track ID, name, artist, and duration. Use this to find tracks before playing or adding to playlists.'
• Document input schemas explicitly in tool registration. For each tool, include JSON Schema with type, description, and constraints for every parameter. Example: search_tracks should document query (string, required), limit (integer, 1 - 50, default 20), offset (integer, default 0).
• Document output schemas. For search_tracks, specify: returns object with 'tracks' array containing {track_id, name, artist, duration_ms, uri}. For get_queue, specify: returns {current_track, queue: [{track_id, name, ...}], total_count}.
• Add parameter descriptions. Every parameter needs a description explaining what it controls, valid range, and format. Example: 'device_id (string, required): The Spotify device ID to transfer playback to. Get available IDs from get_available_devices().'
• Implement error recovery guidance. When a tool fails, return actionable error messages. Example: 'Track not found. Try search_tracks() with a partial name or artist.' instead of a bare 404.

Inferred effective spec: <=2025-11-25.

• Relies on Stateful initialize / Mcp-Session-Id (removed; protocol is stateless) - make each request self-contained