CoinGecko MCP Server

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The annotation readOnlyHint=true already indicates this is a safe read operation. The description adds useful context about what data categories are returned (metadata and market data with specific examples), but doesn't disclose behavioral traits like rate limits, authentication requirements, response format, or pagination. With annotations covering the safety profile, this earns a baseline 3 for adding some value without contradictions.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, well-structured sentence that efficiently conveys the tool's purpose with zero wasted words. It's front-loaded with the core functionality and uses bold formatting for key concepts, making it easy to parse while remaining comprehensive.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a read-only tool with good annotations and high schema coverage, the description provides adequate context about what data is returned. However, without an output schema, it could benefit from more detail about response structure or data formats. The description covers the essential 'what' but leaves some gaps in 'how' the data is organized in response.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is high at 89%, so the schema already documents most parameters well. The description doesn't add specific parameter semantics beyond implying the 'id' parameter is for coin identification. It mentions data categories like 'market data' which loosely maps to the market_data parameter, but doesn't explain parameter interactions or defaults beyond what the schema provides.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the specific verb 'query' and resource 'metadata and market data of a coin from the CoinGecko coin page', with explicit examples of what metadata (image, websites, socials, description, contract address) and market data (price, ATH, exchange tickers) are included. It distinguishes from siblings by specifying it's based on 'coin ID' rather than contract addresses, markets, or other parameters used by other tools.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage context by stating it queries 'based on a particular coin ID', suggesting this is for looking up specific coins rather than lists or markets. However, it doesn't explicitly state when to use this versus alternatives like get_coins_markets (for multiple coins) or get_coins_contract (for contract-based lookup), nor does it mention prerequisites like needing a valid coin ID.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.