SolSpeak TTS demonstrates good overall definition quality with properly registered tools, comprehensive parameter schemas, and detailed descriptions. All 6 tools have documented input schemas with type constraints and descriptions. However, there are notable gaps in error handling guidance, output schema documentation, and some parameter descriptions lack explicit constraints. Tool naming follows verb_noun conventions (text_to_speech, list_voices, delete_voice, clone_voice_from_youtube, set_voice_transcript, generate_conversation). The server excels at parameter documentation with enum constraints (models: standard|turbo|fish) and numeric ranges (exaggeration, cfg_weight, temperature bounds all specified). Descriptions average ~120 chars per tool, which is adequate but could be more LLM-optimized. The MCP_INSTRUCTIONS provide excellent contextual guidance for multi-model usage and emotion markers for Fish model, but this pedagogical content should be supplemented with inline parameter descriptions for error recovery patterns.

• Document return schemas for all tools. E.g., text_to_speech should specify: { "download_url": "string", "duration_seconds": "number", "file_format": "string (wav|mp3)" }.
• Replace password parameter in delete_voice with server-side permission checks. Document required scopes (e.g., 'write:voices'). Use MCP permission-gate pattern.
• Add formal nested schema for generate_conversation 'items' array. Define each element as: { type: 'object', properties: { text: {type: 'string'}, voice_name: {type: 'string'}, model: {enum: ['standard','turbo','fish']}, ... }, required: ['text', 'voice_name'] }.
• Document conditional parameter rules inline. E.g., 'For fish model: voice_text REQUIRED if voice_name provided; temperature, top_p, repetition_penalty apply only to fish model. For standard/turbo: exaggeration, cfg_weight apply only. voice_audio_base64 and voice_name are mutually exclusive.'
• Add error recovery guidance for each tool. E.g., text_to_speech: 'If error includes "voice_name not found", call list_voices() to see available clones.' 'If error includes "model incompatible", retry with different model or provide voice_name for turbo.'
• Add idempotency note in tool descriptions: 'Calling with identical parameters within 60 seconds returns cached result. URLs expire after 24 hours.'
• Expand generate_conversation description to clarify output (single merged WAV file with speakers in sequence) and timing (silence_between applies between clips).
• Add validation hints in descriptions. E.g., clone_voice_from_youtube: 'Timestamp format: MM:SS or HH:MM:SS. Duration 10-15 seconds recommended. If transcript not provided, fish model quality degrades.'