Get document thumbnail

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

Annotations already cover the read-only, idempotent, non-destructive profile. The description adds behavioral context beyond the annotations by specifying that the return is an inline thumbnail image meant to be viewed, which helps the agent anticipate the response format.

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 two concise sentences with no filler. The primary action is front-loaded, and the use-case rationale is expressed in one clause.

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 one parameter and no output schema, the description covers the main purpose, the return nature, and the practical use case. It does not detail image format or size, but this is not critical given the simple signature and read-only annotations.

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?

The schema has 0% description coverage for its single 'id' parameter. The description implies that 'id' refers to the document whose thumbnail is returned, but it does not explicitly document the parameter's meaning or any special formatting. For a single obvious integer id, this is adequate but not exemplary.

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 action ('Return the document's thumbnail image inline') and the resource (the document's thumbnail). It conveys the practical purpose of visually confirming a document, which differentiates it from content-retrieval tools, though it does not explicitly name sibling 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 clear usage context: use it when you want to see what a document is without reading its OCR text. It does not explicitly list alternatives or exclusions, but the implied when-to-use is strong enough for an agent to select it appropriately among siblings.

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