Store screenshot requirements

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds value annotations do not carry by stating 'Credits: free, no credits', which tells the agent there is no cost barrier to calling it. It does not discuss output shape or scope limits, but an output schema exists to cover returns.

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?

Three short sentences, front-loaded with the capability, then the sequence guidance, then the cost note. Nothing is repeated and every clause carries information an agent would act on.

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 single-optional-parameter read tool with an output schema and full annotation coverage, this is complete: it says what comes back, when to call it relative to siblings, and that it costs nothing. No gaps remain that would block a correct invocation.

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% and the single enum parameter is documented as 'Absent: both stores.' The description's phrase 'App Store and/or Google Play' reinforces the optional/default behavior but adds no syntax or format detail beyond the schema, so the baseline of 3 applies.

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 (returns) and resource (the screenshot rules of the App Store and/or Google Play), then enumerates the payload: device classes with required/conditional/optional status, screenshot counts, accepted sizes and formats, and the Play feature graphic. An agent can distinguish this from list_devices or create_screenshot_set without opening any schema.

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?

Gives an explicit ordered workflow: call this first before planning a listing, then list_devices for exact ids, then create_screenshot_set to build everything. Two sibling tools are named with the condition that selects each, so no inference is required.

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