CoinGecko MCP Server

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

The annotation provides readOnlyHint=true, indicating this is a safe read operation. The description adds that it searches 'documentation for how to use the client to interact with the API,' which provides useful context about what kind of information is returned. However, it doesn't disclose behavioral traits like pagination, rate limits, authentication needs, or what happens with no results. With annotations covering the safety aspect, a 3 is appropriate as the description adds some value but not rich behavioral context.

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, clear sentence that efficiently states the tool's purpose. It's appropriately sized for a search tool with three parameters. There's no wasted verbiage or unnecessary elaboration. It could be slightly more structured by explicitly mentioning the parameters, but as a standalone sentence it's well-formed.

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 search tool with 3 parameters, 100% schema coverage, and readOnlyHint annotation, the description is minimally adequate. It explains what kind of content is searched (documentation about API client usage), which is valuable context. However, without an output schema, the description doesn't explain what format results come in or what happens with empty results. The description covers the basics but leaves gaps about result format and edge cases.

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 100%, with all parameters well-documented in the schema. The description doesn't add any parameter-specific information beyond what's in the schema. It mentions 'documentation' which relates to the query parameter, but doesn't provide additional syntax, format, or usage details. Baseline 3 is correct when the schema does the heavy lifting.

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 tool's purpose: 'Search for documentation for how to use the client to interact with the API.' It specifies the verb ('search') and resource ('documentation'), and the scope ('how to use the client to interact with the API') is reasonably specific. However, it doesn't explicitly differentiate from sibling tools, which appear to be cryptocurrency/blockchain data queries rather than documentation search 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 provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites, constraints, or suggest other tools for related tasks. The sibling tools are all cryptocurrency data queries, so this documentation search tool is clearly distinct, but the description doesn't help the agent understand when documentation search is appropriate versus data queries.

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