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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context: the listing is public, available for any store-native id, and includes truncated description/release notes. No contradiction with annotations.

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 tight sentences. The first front-loads the action, resource, scope, and key fields; the second adds the primary use case. There is no redundancy or irrelevant prose.

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?

The description combined with the fully documented schema and output schema gives an agent everything needed to invoke the tool correctly. It covers the operation's purpose, scope, parameter meaning, and return-field expectations without requiring additional explanation.

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 provides rich documentation for all four parameters, including the enum for store and details on the storeId format (Apple id, Google Play package, Microsoft product id). The description adds no parameter-specific guidance, but with 100% schema coverage the baseline is met.

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?

The description uses a specific verb and resource ('Fetch the public store listing for any app by its store-native id'), enumerates the fields returned (title, developer, rating, price, version, etc.), and explicitly differentiates itself from app-tracking tools with 'not just apps tracked in Appskyline'. This is unambiguous and distinguishable from siblings like get_app.

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?

It states a clear use case ('competitor research') and clarifies scope ('any app'), which guides when to use it. It doesn't explicitly name alternatives or state when not to use it, but the sibling names and this scope description provide sufficient context.

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