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

Annotations already declare readOnlyHint=true and openWorldHint=true, covering the safety profile, but the description adds nothing beyond them - no note that results vary by Country storefront, that Ratings/Platforms toggle extra fetches, or what the response contains. A bare fragment leaves the behavioral burden entirely on structured fields.

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?

It is short, but short due to under-specification rather than economy - a four-word noun phrase is not front-loading useful information. No sentence earns its place because there is essentially only one fragment.

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 6-parameter tool with an output schema and annotations, the description should at minimum tell the agent it needs an ID or bundle ID and that Country selects the storefront. As written it omits anything an agent needs to call the tool correctly, relying wholly on schema and annotations.

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%, so baseline 3 applies: the schema already documents ID vs AppID, Lang, Country, Ratings, and Platforms, including the extra-fetch cost of Platforms. The description contributes no additional parameter meaning.

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 fragment "Apple App Store app details" names the resource (an App Store app) and implies a lookup, distinguishing it loosely from appstore_search and appstore_reviews by name alone. However, it never states a verb like 'fetch' and gives no explicit differentiation from siblings such as appstore_ratings, appstore_privacy, or googleplay_app, leaving the agent to infer scope.

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?

There is no when-to-use guidance, no note that this is the detail lookup reached after appstore_search, and no mention of when to prefer it over appstore_ratings or appstore_version_history. The only routing hint (provide ID or AppID) lives in the schema, not the description.

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