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A remote MCP server providing calculator tools without authentication, deployed on Cloudflare Workers
Two tools with basic schemas and minimal descriptions. Both tools have input schemas with proper types (number, string enum), but descriptions are extremely short (10-40 chars), falling well below the 50-200 char baseline for LLM-optimized descriptions. No output schemas documented. Error handling is minimal (divide-by-zero check in 'calculate' returns text, not structured error). Tool names lack action verbs ('add' and 'calculate' are weak; 'perform_addition' and 'perform_calculation' would be clearer). No parameter descriptions beyond type hints. Schemas are present but sparse.
Simple addition tool
Calculator tool with multiple operations
Tool descriptions are critically short (10-40 chars). 'Simple addition tool' and 'Calculator tool with multiple operations' lack context for LLM selection. Should explain WHAT the tool does, WHEN to use it, and what it returns (e.g., 'Adds two numbers and returns their sum as a numeric result. Use when you need basic arithmetic addition.').
Parameter descriptions are missing. Schema shows types (a: number, b: number, operation: enum) but no descriptions explaining what each parameter controls or its valid range. LLMs cannot infer meaning from names alone.
Output schema is not documented. Tools return text content but no schema is declared for clients. LLMs need to know what fields to expect in responses to plan downstream calls.
| Scored | Grade | Overall | Spec posture | Rubric |
|---|---|---|---|---|
| 2026-09-23 | F | 38 | 2026-07-28+ | v2 |
Tool names lack action verbs. 'add' and 'calculate' are weak; they do not clearly signal intent. Rename to 'perform_addition' or 'add_numbers' and 'perform_arithmetic' or 'calculate_result' to match verb_noun convention.
Error handling is minimal and unstructured. 'calculate' returns plain text 'Error: Cannot divide by zero' instead of a structured error response with recovery guidance. Should return {error: 'division_by_zero', message: 'Cannot divide by zero. Provide a non-zero divisor.'}.