Fetch App Store screens

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

Discloses key behavioral traits beyond annotations: it is keyless/free, requires a confident match, returns 0 and saves nothing on ambiguity, saves screens with durable URLs, and makes them immediately usable. These details go well beyond the annotation flags and give the agent an accurate model of execution and failure.

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?

Four sentences, each dense with useful information, and the core purpose is front-loaded. There is slight redundancy around the screens being saved and usable, and the emphatic 'REAL' adds tone but no fact, so it is not a perfect 5.

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 two-parameter tool with no output schema, the description covers defaults, side effects, failure behavior, auth/cost, persistence, and immediate usability. It even implies what a result looks like ('returns 0 screens') sufficiently for an agent to interpret the outcome.

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 already documents both parameters at 100% coverage, including appName's default and brandId's fallback to the active brand. The description mostly restates the appName default without adding deeper semantic value, so the baseline 3 is appropriate.

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 the specific verb 'Pull... App Store screenshots into the workspace brand' with both the resource (App Store) and the side effect (saving into the brand). It names the intended downstream use (make_template_ad(template:'app-ui-tour')), which clearly distinguishes it from generic fetch or list tools in the sibling set.

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?

Explicitly gives trigger conditions: use when the brand has 0–1 app screens on file, when the user asks to 'pull my app's screenshots', or for a specific template. It also tells the agent not to retry with guesses and to relay a zero-result outcome plainly, making when-to-use and when-not-to-use clear.

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