get_document_thumbnail

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the description's addition of 'inline image content' provides useful but minimal behavioral context. It does not discuss edge cases like missing thumbnails or response format details, so the added value is moderate.

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, concise sentence that efficiently conveys the tool's purpose. It is front-loaded with the key action and result, with no unnecessary 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?

For a simple read-only tool with rich annotations and a single parameter, the description covers the core functionality well. However, it omits potential error conditions (e.g., document not found, no thumbnail) which could be helpful but are not critical given the annotations and context.

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 0%, and the only parameter (document_id) is not explained in the description. The parameter name is self-explanatory, but the description fails to add any meaning beyond the schema, such as clarifying it's an integer identifier. With one parameter and low coverage, the description should compensate but does not.

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 returns the document's thumbnail as inline image content, specifying the verb (return) and resource (document's thumbnail). This distinguishes it from siblings like get_document_content (returns full content) and get_document (returns metadata).

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 when a thumbnail is needed, but does not explicitly say when to use it vs alternatives or provide exclusions. Given the clear purpose, the usage context is understood but not articulated.

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