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

Annotations already declare readOnly, idempotent, non-destructive and open-world, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: which fields are returned (observed price, in-app purchase, audience) and, critically, that revenue is neither published nor estimated — preventing false expectations about the payload. It omits pagination/result-cap behavior, which keeps it from a 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?

Two sentences, zero filler, with the result-scope statement front-loaded and the data-limitation caveat placed second where it belongs. Nothing is repeated from the schema or annotations.

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?

With six parameters, a fully-described schema and no output schema, the description supplies what structured fields cannot: the returned field set and the revenue-data limitation. It does not mention how to obtain category/collection ids (only the schema points at list_new_release_categories) or any result-size behavior, leaving a small gap.

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 the schema already documents all six parameters, including the days default/max and the store enum caveat. The description's only parameter-adjacent contribution is the vague phrase "recent window," which adds no format or constraint detail beyond the schema. 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?

The description names a specific resource and scope: apps released to a storefront within a recent window, plus a distinguishing trait (chart position flags for already-ranking apps). That separates it from top_charts and search_store in spirit, but it never explicitly names those siblings and is phrased as a noun phrase rather than a verb-led statement of what the tool returns.

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 by the scope wording ("recent window", "storefront"); there is no explicit when-to-use, when-not-to-use, or named alternative such as top_charts for established rankings or search_store for targeted lookups. An agent can infer the intent but gets no routing guidance.

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