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

Annotations already declare destructiveHint=true, idempotentHint=true, and readOnlyHint=false, so the safety profile is covered. The description adds no extra behavioral context such as what gets purged, whether the action is immediate, or what happens to in-flight image requests.

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 with no filler. It is not front-loaded with the required source_id constraint, but it avoids unnecessary length.

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 destructive cache-purge operation with a sibling that appears to overlap heavily, the description should clarify scope and distinguish usage. The annotations and output schema cover some context, but the description itself leaves critical selection and caution information unstated.

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 documents both parameters. The description adds no meaning beyond that, and it does not clarify the relationship between the required source_id and the paths array.

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 states a purge-cache operation for image paths, which is a clear verb-resource pairing. However, it does not distinguish this tool from the sibling 'purge_image_cache', and the phrase 'any image path' is misleading because a required source_id is needed and paths is an array parameter.

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 gives no guidance on when to use this tool versus alternatives, especially the similarly named 'purge_image_cache'. It omits prerequisites, required permissions, and any conditions that select this tool over siblings.

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