This MCP server exhibits significant definition quality gaps across most tools. While tool names follow verb_noun conventions (get_nutrition, suggest_dishes, lock_dish), parameter descriptions are sparse or missing, input schemas lack complete type definitions, and output schemas are not documented. The validate tool is a security red flag, it requires MY_NUMBER environment variable as a tool parameter, violating secret injection patterns. Most tools have descriptions, but they are verbose and include example values (e.g., '2 eggs', '100g chicken breast') that LLMs tend to reuse literally. Only 2 of 6 tools have complete, typed input schemas visible in the code; others are inferred from Pydantic models not shown. Error handling is absent, no recovery guidance, actionable error messages, or categorization. The server combines API logic with MCP registration, making schema visibility unclear.

• Move MY_NUMBER to server-side environment initialization. Remove it from validate tool parameters entirely. Use fastmcp's built-in authentication or context injection.
• Replace example values in descriptions with formal constraints. E.g., 'amount (number, e.g. 2 for 2 apples)' → 'amount (positive number; e.g. 2 apples, 100 for grams of rice)' + add min/max constraints in schema.
• Document complete input and output schemas for every tool. For lock_dish, define nutrition as: {"type": "object", "required": ["calories", "protein", "carbs", "fat"], "properties": {"calories": {"type": "number", "minimum": 0}, ...}}.
• Add error handling guidance to tool descriptions. E.g., get_nutrition: 'If the food is not recognized, returns status 400 with a list of similar foods. Suggest alternatives to the user or ask for clarification.'
• Document what each tool returns. Add to description: 'Returns: {calories (float), protein (float), carbs (float), fat (float), timestamp (ISO 8601)}' (or actual fields).
• Verify tool registration in fastmcp setup (not shown in source). Ensure @tool decorator or equivalent explicitly registers each tool with name, description, and JSON Schema input.
• Add dependency hints to tool descriptions. E.g., nutrition_board: 'Call this after get_nutrition and lock_dish to see updated totals.'
• For scan_grocery_bill, clarify output: does it return item names only, or quantities? Are items matched to nutrition database entries? Add this to description and output schema.