Single tool with basic structure but significant quality gaps. Tool name 'convert_city_temperatures' is verb-noun compliant and clear. Description is present (89 chars) but lacks WHEN/WHY context and does not explain the bidirectional conversion logic or file format requirements. Input schema exists with one parameter 'filename' (string type, 67-char description), but lacks format constraints, enum values, or validation guidance. No output schema documented, return type is inferred from code (Dict[str, List[Dict[str, float]]]) but not formally specified in tool metadata. No error handling guidance visible; code returns error dicts but tool description does not explain recovery paths. No parameter constraints (file extension, path validation, size limits). Baseline: avg tool description 194 chars (this is 89); avg param description 72 chars (this is 67). Missing: output schema documentation, error recovery guidance, input validation constraints.

• Add formal output schema to tool metadata: {type: 'object', properties: {[city_name]: {type: 'array', items: {type: 'object', properties: {Celsius: {type: 'number'}, Fahrenheit: {type: 'number'}}}}}, error: {type: 'string'}}
• Expand tool description to 150-250 chars explaining: (1) what it does (bidirectional C↔F conversion), (2) when to use it (when you have city temperature data in JSON), (3) what it returns (both units for each city). Example: 'Converts city temperatures between Celsius and Fahrenheit. Reads a JSON file from /data folder with structure {city: {scale: "celsius"|"fahrenheit", values: [...]}} and returns both units for each temperature.'
• Document expected JSON input format in parameter description: 'Name of JSON file in /data folder. File must contain object with city names as keys and objects with "scale" ("celsius" or "fahrenheit") and "values" (array of numbers) as values. Example: {"Paris": {"scale": "celsius", "values": [15, 20, 25]}}'
• Add error handling guidance to description: 'Returns error dict if file not found or malformed JSON. Ensure file exists in /data folder and is valid JSON.'
• Add parameter constraints: specify file extension (.json), path validation (no traversal), and size limits to prevent abuse