AytchMCP defines 3 tools with basic structure but significant quality gaps. Tool names follow verb-noun convention (echo, weather, calculator), but descriptions are minimal and lack LLM-optimization guidance. Parameter schemas are present with types and descriptions, but lack constraints (enums, ranges, format hints). No output schema documentation visible. Error handling is absent, no guidance on invalid inputs, recovery paths, or actionable error messages. The 'weather' tool description is vague ('Get weather information') without specifying what data is returned or what format 'location' accepts. The 'calculator' tool exposes direct expression evaluation without validation guardrails, creating injection risk. No tool returns a documented schema, limiting agent ability to chain operations downstream.

• Add explicit output schema documentation for each tool. E.g., for weather: 'Returns object with temperature (number), humidity (0-100), conditions (string), and sunrise/sunset times (ISO 8601).'
• Expand tool descriptions to 100-150 characters. For weather: 'Fetches real-time weather data (temperature, humidity, conditions, forecast) for a given location. Supports city names, coordinates (lat,lon), or postal codes. Defaults to Fahrenheit.'
• Add parameter validation rules in descriptions. E.g., 'units: One of [celsius, fahrenheit, kelvin]. Defaults to fahrenheit.' For calculator: 'expression: Mathematical expression with +, -, *, /, ^, sqrt, sin, cos, tan only. Max 200 chars. Invalid operators return error.'
• Document enum values explicitly. Instead of 'units: Temperature units', write 'units: One of [celsius, fahrenheit, kelvin]'.
• Add error guidance to each tool. E.g., 'If location not found, try a nearby city name. If network timeout, retry after 30s.'
• Implement input sanitization for calculator tool. Use a safe math parser (sympy, ast.literal_eval) instead of eval(). Reject unknown operators, limit recursion depth, and timeout long-running expressions.
• Add idempotence guarantee documentation. E.g., 'echo is idempotent, calling multiple times with same input yields same output.'
• Document rate limits and timeouts. E.g., 'weather: 60 requests/minute per IP. 5s timeout. Returns 429 Too Many Requests if exceeded.'
• Return full reference IDs in responses for chaining. If weather returns a location, include a location_id or location_code so agents can link to other location-specific tools.

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

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