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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 info. 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. Use when you need basic arithmetic addition.').
Parameter descriptions are missing. Input schema defines 'a', 'b', and 'operation' with types but no descriptions. LLMs cannot infer that 'a' and 'b' are operands or that 'operation' must be one of the enum values. Add descriptions like 'First operand (number)' and 'Arithmetic operation to perform: add, subtract, multiply, or divide'.
Output schema is not documented. Both tools return text content, but the LLM has no formal schema describing the response structure. Document: 'Returns {content: [{type: "text", text: string}]}' or similar.
| Scored | Grade | Overall | Spec posture | Rubric |
|---|---|---|---|---|
| 2026-09-23 | F | 40 | 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_calculation' or 'calculate_arithmetic' to match the verb_noun pattern and improve LLM disambiguation.
Minimal error handling. Only 'calculate' checks for divide-by-zero; 'add' has no validation. Error messages should guide recovery: 'Cannot divide by zero. Try a different divisor or use the add/subtract/multiply operations instead.' No guidance for invalid operation enum values.