Single tool 'calculator' has a clear name and basic schema, but lacks depth in descriptions and error guidance. Tool description is 104 chars (within baseline 34-392 range) but generic. Parameters have types and descriptions (baseline met: 72 chars avg), but no guidance on constraints, error recovery, or when to use this tool vs alternatives. No output schema documented. Error handling is minimal, division by zero returns a generic error without recovery guidance. No tool annotations (readOnlyHint, idempotentHint). Overall: functional but below production quality.

• Add an explicit output schema: {"type": "object", "properties": {"result": {"type": "number", "description": "The result of the arithmetic operation"}}, "required": ["result"]}
• Expand tool description to 150-250 chars: 'Performs basic arithmetic (add, subtract, multiply, divide) on two numbers. Use when the user asks for a calculation. Returns a numeric result. Supports integers and decimals; division by zero returns an error.'
• Add tool annotations in the tool definition: "readOnlyHint": true, "idempotentHint": true to signal safety to LLMs.
• Enhance error messages with recovery guidance: 'Division by zero error. Ensure the second number (b) is not zero, then retry.' and 'Missing required parameters: operation, a, b. Provide all three to execute the calculator.'
• Clarify parameter constraints: 'a: First operand (number, supports integers and decimals, e.g., 5 or 3.14)' and 'b: Second operand (number, same format; must be non-zero for divide operation).'