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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=true, so the safety and idempotency profile is fully covered. The description adds only the return-field list (name, developer, price, rating, version, genres, link) and says nothing about rate limits, quotas, or partial-failure behavior when some ids fail — acceptable given annotation coverage but not rich.

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 with the capabilities front-loaded and the return shape second — nothing wasted. Slightly dense mode enumeration, but each clause carries a distinct mode so it earns its space.

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 an 11-parameter, zero-required tool with no output schema, the description covers both the operation set and the response fields an agent would need to plan a call. Defaults, enum-like values and limits live in the schema, so the only gap is behavioral edge cases, which the annotations largely carry.

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 every parameter already documents its semantics (mode defaults, up-to-50 ids, page 1-10, chart types, country codes). The description only echoes 'per country' and 'by id or bundle id'; it adds no syntax or format detail beyond the schema, so the 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?

Names a specific resource (Apple App Store) and enumerates the four distinct operations it supports: search, id/bundle-id lookup, reviews, and top charts per country. It also lists the returned fields, so an agent knows exactly what capability it is selecting 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?

The enumeration of modes ('search... look apps up by id or bundle id, read customer reviews, or get the top free, paid and grossing charts, per country') implicitly routes the agent to the right mode, and the schema's mode param spells out the defaults. No sibling tools compete — the other 16 tools are unrelated (email, domain, SEC), so no exclusions are needed.

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