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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' only). Tool names lack action verbs ('add' and 'calculate' are weak; 'perform_addition' and 'perform_calculation' would be clearer). No parameter descriptions beyond type hints. No composition guidance or chaining metadata.
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 text response').
Parameter descriptions are missing. Zod schema defines types (z.number(), z.enum()) but provides no descriptions for 'a', 'b', or 'operation'. LLMs cannot infer whether 'a' is a count, price, or index. Each parameter needs a 1-2 sentence description.
Output schema is not documented. Both tools return {content: [{type: 'text', text: string}]} but this structure is not declared in any schema or description. LLMs cannot plan downstream calls or extract structured data without knowing the response format.
| Scored | Grade | Overall | Spec posture | Rubric |
|---|---|---|---|---|
| 2026-09-23 | D | 50 | 2026-07-28+ | v2 |
Tool names lack action verbs. 'add' and 'calculate' are generic. Stronger names like 'perform_addition' or 'perform_arithmetic' would clarify intent. Current names risk LLM confusion if other math tools exist.
Error handling is minimal. Only 'calculate' checks for divide-by-zero; 'add' has no validation. Error messages should guide recovery (e.g., 'Cannot divide by zero. Use the add, subtract, or multiply operations instead.').