Simple MCP server with two basic tools. Both tools have verb-based names and descriptions, but descriptions are minimal (16-20 chars), falling below the 34-392 char baseline and below the 10-1024 char recommendation. Parameters are properly typed (integer/string) with required constraints, but completely lack descriptions, every parameter is undescribed. No documented output schemas, no parameter constraints beyond type, and no error handling guidance. The tools follow the tool_router pattern correctly with explicit #[tool] macros, but fall short on documentation completeness needed for production LLM use.

• Add descriptions to all parameters. For 'add': describe 'a' as 'First number to add (integer, range -2147483648 to 2147483647)' and 'b' as 'Second number to add (integer, range -2147483648 to 2147483647)'. For 'echo': describe 'message' as 'Text string to echo back (non-empty, max 1000 chars)'.
• Expand tool descriptions to 50-200 characters. 'add': 'Add two integers together and return the sum. Use this to perform basic arithmetic calculations.' 'echo': 'Echo back a provided message with an 'Echo: ' prefix. Useful for testing communication or mirroring user input.'
• Define and document output schemas in the tool definition. Create a JSON Schema fragment for MathResponse (result: integer, operation: string) and EchoMessage (message: string) and reference it in the tool registration.
• Add input schema constraints: mark the 'message' parameter in echo as minLength: 1, maxLength: 1000 to prevent empty or huge inputs.
• Implement error handling with recovery guidance. If integer overflow occurs in add, return a clear error: 'Addition result exceeds range [-2^31, 2^31-1]. Provide smaller numbers.' Include actionable next steps.

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

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