List screenshots and app previews

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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds meaningful context beyond that: results carry Apple's processing state or errors, which tells the agent that returned media may not yet be live and that failures surface here. Pagination and volume/rate behavior are still unstated.

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?

Two sentences, no filler, with the resource and returned fields front-loaded and the usage hint last. Every clause earns its place.

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?

With 7 optional parameters and no output schema, the description does the needed work of enumerating the return shape so an agent can interpret results. It stops short of explaining the target/localizationIds relationship for custom product pages and experiment treatments, which is the one part of the input contract left implicit.

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 baseline is 3 and every parameter is already self-documented. The description's 'per language and device size' framing reinforces the locales grouping but adds no syntax or precedence detail, e.g. it doesn't say how versionId, appId, and versionString interact when several are supplied.

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?

States a specific verb and resource: screenshots and app preview videos of an App Store version, scoped per language and device size. It also previews the returned payload (file names in display order, sizes, processing state or errors), so an agent knows exactly what it gets back without opening anything else.

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 line 'Use it before and after uploading' gives a timing hint (verify state before/after a media upload), which is real guidance. However, it names no alternative tool or condition for choosing between targets such as version vs customProductPage vs experimentTreatment, so selection still has to be inferred from the schema enums.

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