The server defines 8 tools with explicit, complete JSON Schema input definitions and descriptions in English and Chinese. All tools follow a consistent verb_noun naming convention (get_*). However, descriptions are minimal (10-20 chars avg), lacking the 50-200 char LLM-optimized length and WHEN/WHY context. No output schemas are documented. Parameter descriptions exist but are terse. No error handling guidance, no idempotency markers, and security posture is weak (API key required but no secret injection pattern). Tools are read-only and well-constrained with enums and min/max bounds, which is good. Tools show clear single responsibility (each targets one weather data type), supporting composition. Average across 8 tools yields mid-50s, fair baseline for a simple domain tool, but well below 70 for production readiness.

• Expand each tool description to 50-200 chars with explicit WHAT/WHEN/WHAT-RETURNS format. Example: 'Get current and forecast weather by geographic coordinates. Use this when you have latitude/longitude (e.g., from a map or geolocation API). Returns real-time temperature, conditions, humidity, and hourly/daily forecasts configured via daily_steps and hourly_steps parameters.'
• Document all output schemas. Add a 'Returns' section to each tool describing the structure: { realtime: { temperature, humidity, condition }, hourly: [], daily: [] }. Example: 'Returns object with realtime (current conditions) and forecast arrays (hourly up to 360, daily up to 15).'
• Translate all parameter descriptions to English. Change properties.longitude.description from '经度' to 'Geographic longitude in decimal degrees (-180 to 180). Required.'
• Add error handling guidance in descriptions. Example: 'If coordinates are out of bounds, error response will indicate valid range. If the API rate limit is exceeded, retry after 60 seconds.'
• Add tool annotations in the tool registration. Mark all 8 tools with 'readOnlyHint: true' and 'idempotentHint: true' so clients know they are safe to retry and do not modify state.
• Implement server-side API key injection without exposing to parameters. Remove --api-key command-line parsing. Use only environment variable CAIYUN_API_KEY, and fail safely before server init if missing.
• Add input validation with actionable error messages. When coordinates are invalid, return: { error: 'Invalid latitude: must be -90 to 90, received: <value>' } instead of a generic 500 or constraint violation.