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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so safety is covered. The description still adds useful behavior beyond them: results are live rather than cached, the actual fields returned are enumerated, and each item carries an apppage_url for follow-up detail.

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 sentences, zero padding, with the core purpose and the return summary front-loaded and the sibling routing placed last. Every sentence earns its place.

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?

There is no output schema, but the description enumerates the returned fields (ids, titles, developers, ratings, prices, apppage_url), which is exactly what the missing output schema would have supplied. Combined with annotations and a fully documented input schema, nothing an agent needs 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 description coverage is 100% and all four parameters are fully documented in-schema (limit range/default, store enum, country ISO codes). The description only restates the keyword concept and the store selection, adding no syntax or constraint detail on top.

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 and resource ('Search Google Play or App Store apps by keyword') with the scope qualifier 'live results'. It also distinguishes itself from the get_app sibling explicitly, so an agent can route without opening the 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?

'Use get_app for details of one app' gives a clear alternative and the condition that selects it. Beyond that one routing rule there is no explicit guidance on when not to use this tool (e.g., known app id vs keyword).

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