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 useful non-annotation context: the per-call cost (100 points), the default country, and the 10-page pagination ceiling, all of which shape whether and how an agent calls it.

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 short sentences, front-loaded with what the tool returns before defaults and cost. The English/Korean duplication is redundant but conventional for this toolset and does not obscure the key information.

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 no-output-schema read tool, the description covers purpose, keying parameter, defaults, pagination limit, and cost. It omits return shape beyond a parenthetical field list, but that is a minor gap given the tool's simplicity and the read-only annotation.

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 each schema field already states its default and bounds (page 기본 1/최대 10, country 기본 kr, appId numeric). The description restates the same defaults, adding no syntax or format detail beyond the schema, 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+resource (get iOS app metadata and customer reviews) and the keying scope (numeric app id), even enumerating the metadata returned (rating, price, genre). Among ~100 siblings, none covers iOS app reviews, so an agent can unambiguously route here.

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: the description says what the tool fetches, so the agent infers it should be called when iOS app info/reviews are wanted. There is no explicit when-to-use framing, no when-not guidance, and no alternative named (though no close sibling exists).

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