Single tool 'get_crypto_price' has a clear action verb and reasonable input schema with type definitions. However, the tool lacks critical documentation and structure expected of production-grade tools. The schema is present but incomplete (no output schema documented). Parameter descriptions are minimal (coin_id and currency both have basic descriptions but lack constraints, examples, or error guidance). No error handling guidance is provided to LLMs on what to do when a coin is not found or the API fails. The tool description is 93 characters, within acceptable range but lacks context on when to use it vs. alternatives, prerequisites, or expected output structure. No tool annotations (readOnlyHint, destructiveHint, idempotentHint) are present. The implementation handles errors internally but does not communicate error recovery paths to the LLM in a structured way.

• Add an explicit output schema documenting the response structure. Example: { type: 'object', properties: { coin_id: { type: 'string' }, currency: { type: 'string' }, price: { type: 'number' }, formatted_price: { type: 'string' } }, required: ['coin_id', 'currency', 'price', 'formatted_price'] }
• Replace free-form 'currency' string with an enum constraint: { type: 'string', enum: ['usd', 'eur', 'gbp', 'jpy', 'aud', 'cad', 'vnd'] } (or expand with all supported CoinGecko currencies)
• Enhance tool description to ~150-200 chars with output clarity: 'Fetch real-time cryptocurrency prices from CoinGecko. Returns the price in the specified currency as a formatted string (e.g., $45,000.50 USD). Call this to get current market rates. Coin must exist on CoinGecko (e.g., bitcoin, ethereum); use lowercase, hyphenated IDs.'
• Add error recovery guidance in the description: 'If coin not found, verify the coin_id is lowercase and hyphenated (e.g., 'solana', not 'Solana'). Supported currencies: usd, eur, gbp, jpy, aud, cad, vnd, and 150+ others.'
• Implement readOnlyHint and idempotentHint annotations in the tool definition to signal to agents that this is a safe, repeatable read operation.
• Remove example currency codes from the parameter description and use a formal enum constraint instead.
• Add a 'limit' or 'precision' parameter if the tool supports custom rounding or decimal places, with clear constraints (e.g., 0-8 decimals).
• Consider adding a companion tool 'list_supported_coins()' or 'search_coins(query)' to help agents discover valid coin_ids without blind guessing.