Store top chart

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

Annotations already cover the safe-read profile (readOnlyHint, openWorldHint), and the description usefully adds that the raw API returns bare app ids with no names or rank numbers while this wrapper injects both, plus the plain-text 422 error format. It stops short of describing pagination, auth, or how limits interact with resolve_names.

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 tight sentences: what it returns, what the wrapper adds, and how to get valid enum values. Front-loaded with the identifying information and no wasted clauses.

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 10-parameter, no-output-schema tool, the description supplies the return-shape details (rank-ordered bare ids plus added names/rank numbers) and the error behavior that the schema cannot. Nothing essential for correct invocation 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 already 100%, so the baseline is 3; the description elevates it by explaining where valid category/chart_type values come from (sensortower_reference) and by flagging the store-specific nature of the endpoint. It adds a little meaning beyond the schema's own parameter descriptions.

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 precise verb+resource: the App Store / Google Play top chart for a given category, country and date, and notes it targets a single store rather than a unified endpoint. It does not explicitly differentiate from nearby siblings like sensortower_top_apps or sensortower_top_publishers, so it stops short of 5.

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 a concrete routing instruction: fetch valid category and chart_type values from sensortower_reference, and warns that a bad value produces a 422 in plain-text form. It offers no guidance on when to prefer this chart tool over sibling ranking tools, so it lacks an exclusion clause.

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