MCP Gemini Server

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

No annotations are provided, so the description carries the full burden. It mentions the client restriction (not supported on Vertex AI) which is useful behavioral context, but it doesn't disclose other traits like whether this is a read-only operation, potential rate limits, authentication needs beyond the API key mention, or what the metadata includes. For a tool with zero annotation coverage, this leaves significant gaps.

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 appropriately sized with three concise sentences. The first sentence states the core purpose, the second provides critical behavioral context (client restriction), and the third clarifies parameter usage. Every sentence earns its place with no wasted words.

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?

Given the simple single parameter with full schema coverage and no output schema, the description is reasonably complete for a basic retrieval operation. However, without annotations and with sibling tools available, it could better address differentiation and provide more behavioral context about what metadata is returned and any limitations.

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%, so the schema already fully documents the single parameter (fileName). The description adds minimal value by restating the parameter requirement and example format, but doesn't provide additional semantics beyond what's in the schema. This meets the baseline for high schema coverage.

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 verb ('Retrieves') and resource ('metadata for a specific file previously uploaded to the Gemini API'), making the purpose unambiguous. However, it doesn't explicitly differentiate from sibling tools like gemini_listFiles or gemini_uploadFile, which would be needed for a perfect score.

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 some context about when to use it (for retrieving metadata of a previously uploaded file) and includes a warning about unsupported clients, but it doesn't explicitly state when NOT to use it or mention alternatives like gemini_listFiles for listing files instead of getting metadata for a specific one. The guidance is implied rather than explicit.

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