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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuinely non-structured information: a per-call cost of 30 points and the 10-page review cap, both of which affect invocation decisions. It does not say how many reviews per page or whether results are paginated/sorted, keeping it below 5.

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?

Short and front-loaded: what it does, what it returns, defaults, and cost in that order. Minor waste from the English and Korean sentences largely restating each other, though the Korean version does add field detail (rating, price, genre).

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?

No output schema exists, and the description does cover both halves of the return (app metadata fields and customer reviews), the cost, and the pagination limit. Missing only secondary details like reviews per page or ordering, which is acceptable for a simple 3-parameter read tool.

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 page, appId and country are already documented with defaults and bounds in the schema. The description restates the same defaults (country kr, page max 10) without adding format, semantics or edge-case guidance, so baseline 3 applies.

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 ('Get iOS app metadata and customer reviews'), plus the keying mechanism ('by numeric app id'). The 'iOS' scope and 'reviews' payload clearly separate it from the many product/metadata siblings (amazon_product, coupang_product, youtube_metadata) without needing those names.

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?

Usage is only implied: it describes defaults (country=kr, page up to 10) and cost, so an agent can infer this is a read call on a known App Store id, but there is no explicit when-to-use or when-not-to-use statement and no named alternative.

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