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

Annotations already mark the operation as read-only and non-destructive, and the description adds meaningful behavioral context by explaining that visibility mirrors the parent submission's visibility ('public once submitted, otherwise limited'). This goes beyond the annotations and helps an agent anticipate access restrictions.

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 tight sentences with no filler. It front-loads the primary action and resource, then supplies the key visibility caveat, making it easy for an agent to parse quickly.

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 list operation with full parameter schema and read-only annotations, the description provides enough context. It could mention the returned media type more explicitly, but the core behavior and access scoping are adequately covered.

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 input schema fully documents all three parameters, including page, page_size, and submission_id, so the baseline is 3. The description does not add parameter-level details, but none are essential given the 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 uses a specific verb ('List') plus a specific resource ('screenshots/gallery images attached to a submission'), making the tool's function immediately clear. It is easily distinguished from sibling tools like submission_get or submission_page because it targets attached media rather than general submission content.

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 use when a user needs to retrieve media attached to a submission, but it does not explicitly say when to prefer this tool over nearby alternatives such as submission_get or submission_page. The visibility context is useful but not a substitute for direct usage guidance.

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