Weather MCP has 8 tools with consistent naming (verb_noun pattern: GetCurrentWeather, GetWeatherForecast, etc.) and reasonable descriptions (100-150 chars, within baseline 194 avg). All tools are READ_ONLY and have basic input schemas with type declarations. However, output schemas are completely undocumented, tools return formatted strings rather than structured JSON, forcing LLMs to parse unstructured text. Parameter descriptions are minimal (10-30 chars) and lack constraints (e.g., GetWeatherForecast 'days' parameter has no min/max in schema, only in description). Error handling is present but generic ('❌ Error: ...'). No pagination, no field-level documentation, no guidance on when to use CompareWeather vs calling GetCurrentWeather twice.

• Convert all tool responses from formatted strings to structured JSON. E.g., GetCurrentWeather should return {temperature: {value: 22, unit: 'C'}, humidity: 65, conditions: 'Partly Cloudy', ...} instead of '🌡️ Temperature: 22°C...'.
• Add formal schema constraints: GetWeatherForecast.days should have {type: 'integer', minimum: 1, maximum: 5} in the JSON Schema, not just in description.
• Expand parameter descriptions to 50-100 chars with format hints. E.g., 'City name (e.g., New York, London, Tokyo), 2-50 characters, required' instead of 'The name of the city to get weather for'.
• Document output schema for each tool. Specify which fields are always present, which are optional, and their types. E.g., GetCurrentWeather returns {temperature: number, humidity: number, conditions: string, ...}.
• Improve error messages with recovery guidance. E.g., 'City not found: {city}. Try search_cities() with a partial name, or check spelling.' instead of generic exception text.

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

• Relies on Logging (deprecated) - log to stderr or use OpenTelemetry