Single tool 'get_weather' has critical definition gaps. Tool name is acceptable (verb_noun pattern), but description is minimal (Chinese-only, 12 chars in English equivalent). Input schema exists with basic type info but lacks constraints, ranges, or format guidance. No output schema documented, response is free-form formatted text, not structured JSON. No error handling guidance for missing cities, API failures, or timeout scenarios. Parameter 'city' has no description in the schema (only in docstring). Tool lacks idempotency guarantees and does not follow response-shaper pattern for structured output.

• Add structured output schema: return JSON object with fields {temp: number, feels_like: number, condition: string, humidity: number, wind_speed: number, wind_direction: string, pressure: number, visibility: number, observation_time: string} instead of formatted text.
• Add parameter description to schema: 'city' should have description 'City name (e.g., Beijing, Shanghai). Required. Accepts Chinese or English names.'
• Implement error handling with actionable messages: return {error: 'City not found', suggestion: 'Try a major city name like Beijing or Shanghai'} instead of empty string.
• Translate tool description to English: 'Get current weather for a city' instead of Chinese. Ensure description is 50-200 characters and explains when to use this tool.
• Add input validation: reject empty city strings, validate length (1-100 chars), and return clear error message with constraint details.

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

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