Three tools with basic schemas and descriptions, but significant gaps in parameter documentation and output schema clarity. Tool names lack action verbs (add, calculate_bmi, fetch_weather are acceptable but minimal). Descriptions are present but brief (10-50 chars), below the 194-char baseline for production tools. Parameter descriptions exist but lack constraints, ranges, or format guidance. No output schemas documented. Error handling absent. Chinese descriptions reduce LLM clarity in English-first environments.

• Expand tool descriptions to 100-200 chars. Example: 'add' → 'Add two integers and return the sum. Use this for arithmetic operations. Returns an integer result.'
• Document output schemas explicitly. Add return type hints and describe the structure: 'Returns: int (the sum of a and b)' or 'Returns: dict with keys {weather: str, temp: int, humidity: int}'.
• Add parameter constraints to descriptions. Example: 'city: string, 6-digit city code (e.g. 110000 for Beijing) or city name in Chinese. Required.'
• Implement error handling for fetch_weather: catch HTTP errors, timeouts, and invalid city codes; return actionable messages like 'City not found. Try a 6-digit code or common city name.'
• Translate descriptions to English or provide bilingual descriptions. LLMs trained primarily on English benefit from English-first tool documentation.