This is a minimal arithmetic/greeting server with serious definition gaps across all tools. While tool names are simple action verbs (add, subtract, greet, divide), parameter descriptions are completely missing (null values in schema), and descriptions are extremely brief (5-7 words). No error handling documentation, no output schemas, no parameter constraints or ranges. The divide tool lacks any mention of zero-division handling. Tools are READ_ONLY but not annotated with idempotentHint or readOnlyHint. This server would score in the D-F range in production contexts.

• Add descriptive, LLM-optimized parameter descriptions in the schema. E.g., 'a' → 'The first number (float, range -1e9 to 1e9)'; 'b' → 'The second number (float, range -1e9 to 1e9)'. Each description should be 20-100 chars, not null.
• Expand tool descriptions to 100-200 chars following the pattern: what does it do (e.g. 'Returns the arithmetic sum a+b'), when to use (e.g. 'Use this when the user asks for addition'), and what you get (e.g. 'Returns a single float value'). Example: 'Add two numbers together. Returns the arithmetic sum. Use when the user asks for addition of numeric values.'
• Document output schemas explicitly. Add a note like 'Returns: {"result": float}' or 'Returns a single float representing the sum of a and b'.
• Add error handling to divide() and document it: 'If b is zero, returns an error: "Cannot divide by zero. Try a different divisor."' Then implement that in code (check b != 0 before dividing).
• Add parameter constraints in descriptions: 'a: float, range -1e9 to 1e9' and 'b: float, range -1e9 to 1e9 (excluding 0 for divide)'.
• Register tools with tool annotations if using fastmcp ≥3.1.0. Use readOnlyHint=true and idempotentHint=true for all four tools to signal to agents these are safe to retry.
• Consider splitting greet() into a separate category or adding context: is this a customer greeting, internal tool, or demo? Current description 'Greet a person' doesn't disambiguate when an agent has 100 tools.