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

With no annotations at all, the description carries the full disclosure burden. It does add genuine behavioral context — this is a 'saved' snapshot and data begins at 2026-11-06 — but it says nothing about what happens when no snapshot exists for a requested date, whether results are paginated, or what authentication/limits apply.

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?

A single dense clause with the resource up front, the scoping dimensions next, and the data-availability bound last. Nothing is redundant or padded.

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 6-parameter read tool with no output schema and no annotations, the description covers the query dimensions but not the payload. It does not convey that the result is a ranked list of apps with positions, or how the default limit of 25 affects shape, leaving the agent to discover the return format.

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 67%, with the date, limit, country, and category parameters already documented in the schema, so the baseline of 3 applies. The description reinforces the country/day/store dimensions but adds no format or constraint detail beyond what the schema states.

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 concrete resource (a saved top chart), the two stores it covers, and the country/day scope, which is enough to tell it apart from siblings like get_app_rank_history and search_apps. It is a noun phrase rather than a verb, so the retrieval action is implied rather than stated, but the subject matter is unambiguous.

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?

There is no when-to-use guidance and no mention of the sibling tools (get_app_rank_history, get_top_trends, search_apps) that an agent could confuse this with. An agent must infer from the name alone that this returns a ranked chart listing rather than per-app rank history.

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