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

With no annotations provided, the description carries the full burden of behavioral disclosure. It explains the important measured=false distinction, clarifies that timeline lists detected listing changes, and scopes what fields are and are not included. It does not mention rate limits, freshness, or explicit read-only guarantees, but it covers the key semantic traps for a retrieval tool.

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?

The description is dense but every sentence contributes distinct information: what is returned, what timeline means, and what measured=false signifies. The first sentence is somewhat heavy with parentheticals and long lists, but it is well front-loaded and avoids fluff.

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?

There is no output schema and no annotations, so the description is the sole source for return semantics. It covers the main returned fields and the two tricky fields, but it fails to clarify the default behavior when the optional country parameter is absent. Given the description stresses 'for one country,' an agent needs to know which country is used by default.

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 both appId and country are already documented. The description reinforces the one-country scope but adds little parameter-level meaning. Notably, country is optional in the schema, yet the description does not state what happens when it is omitted, leaving a meaningful ambiguity.

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 opens with a direct statement that the tool returns the app's own store listing signals, then enumerates concrete fields such as version, in-app events, editorial placements, screenshots, install count, and rating histogram. It also explicitly notes what is excluded (name and subtitle), making the tool clearly distinguishable from siblings that target charts, keywords, reviews, or rivals.

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 description provides meaningful context by calling the timeline 'the cheapest explanation for a rank move,' which implies when an agent would want this tool. However, it never explicitly names alternatives or states when not to use this tool versus siblings like get_charts or get_history, so guidance remains implied rather than explicit.

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