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

Annotations provide readOnlyHint=true, and the description aligns with that (no contradiction). The description adds 'generation_id' as the required identifier and notes it's 'Free', which is useful context beyond the schema. However, it does not explain what a 'cutout' is, whether URLs expire, or any rate limits. For a read-only tool, this is adequate but not rich.

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 concise and front-loaded with the key information: 'Fresh signed URLs for an existing cutout by generation_id. Free.' Two short sentences, no filler. It efficiently communicates the tool's function and cost.

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 schema (one required parameter) and readOnlyHint annotation, the description is fairly complete. It tells the agent what it returns (fresh signed URLs) and how to identify the cutout (generation_id). It lacks details like URL expiration or how to obtain a generation_id, but for a straightforward read operation, this is sufficient. The presence of annotations and simple schema lowers the bar.

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 one parameter, generation_id, with no description. Schema description coverage is 0%, so the description must compensate. The description does mention that the cutout is identified by generation_id, adding some context about the parameter's purpose. However, it does not explain the format (e.g., UUID, string) or any constraints. Baseline is 3 due to zero coverage, and the description just meets that.

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 'Fresh signed URLs for an existing cutout by generation_id' clearly indicates the tool returns signed URLs for a specific cutout, using a verb (get) and a resource (cutout files). However, the term 'cutout' may not be familiar; it is likely a generated image asset. It distinguishes from siblings like get_asset or get_video by the specific 'cutout' and 'generation_id' concept.

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 you need fresh signed URLs for a cutout, but it does not explicitly state when to use this tool instead of alternatives like get_asset or get_detections. It does not mention prerequisites (e.g., generation_id from a prior generation) or conditions where it should not be used.

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