Fetch App Store screens

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

Annotations already declare this a non-readonly write (readOnlyHint=false) with openWorld access and idempotency. The description adds genuinely useful context beyond them: it is FREE/keyless, needs a confident match, and ambiguous lookups save nothing. It does not, however, describe where screens are stored beyond 'durable URLs' or any limits on count.

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?

Front-loads the core action and keeps each subsequent sentence purposeful (trigger, param default, cost, failure mode, success outcome). Dense but not padded; slightly long versus the minimum needed.

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 no output schema, the description carries the full burden and does so: it covers the success result (screens saved with durable, immediately usable URLs) and the failure result (0 screens, nothing saved). Nothing an agent needs to call and interpret it is missing.

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 coverage is 100%, so appName (defaults to saved brand name) and brandId (profile id/name from list_brands) are fully documented in the schema. The description only restates the appName default, adding no syntax or format detail beyond schema — baseline 3.

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+resource: pulling a brand's REAL App Store screenshots into the workspace brand. It distinguishes itself from siblings by naming the companion tool it feeds (make_template_ad with template:'app-ui-tour'), so an agent can route correctly without opening a 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 explicit trigger conditions ('brand has 0-1 app screens on file', 'user asks to pull my app's screenshots') and names the downstream consumer. It also prescribes behavior on failure: relay the 0-screen result plainly rather than retrying with guesses.

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