The server exposes two simple tools with basic schema definitions and minimal descriptions. Both tools have explicit JSON Schema definitions via Zod, which is positive. However, descriptions are extremely terse (12-46 characters), well below the 50-200 character LLM-optimized baseline for A+ tools. Parameter descriptions exist but lack depth on constraints, error conditions, or usage context. The tools follow a simple verb_noun pattern ('add', 'calculate') but lack the comprehensive context needed for production-grade agent planning. Error handling is minimal, the 'calculate' tool handles division by zero inline but returns plain text rather than structured error guidance. No evidence of parameter type sufficiency documentation, rate limiting, or recovery guidance. The 'calculate' tool shows compound functionality (multiple operations in one tool) which is acceptable for a simple utility but could be more composable. Output is always plain text content, which is simple but not machine-optimized for downstream tool chaining. Overall, this is a functional but minimal implementation that would benefit from richer descriptions and structured error handling.

• Expand 'add' description from 'Simple addition tool' to ~100 characters: 'Adds two numbers and returns the sum. Use this for basic arithmetic when you need to combine or total numeric values. Returns a single numeric result.'
• Expand 'calculate' description to clarify operation selection: 'Performs arithmetic operations (add, subtract, multiply, divide) on two numbers. Choose operation based on the math needed. Handles division-by-zero gracefully by returning an error message rather than crashing.'
• Add per-parameter descriptions in the Zod schema. Instead of relying on implicit type info, document: 'a: First operand (any real number)', 'b: Second operand (any real number)', 'operation: The arithmetic operation to apply (add|subtract|multiply|divide)'.
• Return structured error responses for division by zero: { success: false, error: { code: 'DIVISION_BY_ZERO', message: 'Cannot divide by zero. Check the numerator and denominator values.', retryable: false } } instead of plain text.
• Document output schema in tool definitions. Specify: 'Returns { content: [{ type: "text", text: string }] } where text is the numeric result or error message as a string.'
• Add parameter constraints in descriptions: 'a and b: numeric operands, any real number (no bounds enforced, but very large values may lose precision)'.
• Consider splitting 'calculate' into individual operation tools (add, subtract, multiply, divide) for finer LLM reasoning, or keep unified but add return type documentation showing what fields downstream tools can extract.