Competitor facts

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 genuine behavioral facts the annotations cannot: Google Play returns an empty list because its page has no reliable dates, ids absent from the response mean the app is not in that store, and a 50-id ceiling applies.

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 tight sentences with no filler; the field list is front-loaded and the caveats (empty Play result, missing ids, id cap) follow. The leading fragment 'For App Store ids (e.g. competitors from get_board) in one store:' is slightly elliptical but still efficient.

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 no output schema, the description carries the return-shape burden and does so by naming every returned field. Combined with the empty-list rule, missing-id rule and id ceiling, an agent has everything needed to call it and interpret the response.

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 coverage is 100%, so the baseline is 3, and the description adds provenance for 'ids' (competitors from get_board) and restates the 50-id cap that constrains the array. It gives no extra semantics for 'country' beyond the schema's own ISO code explanation.

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 enumerates exactly what is returned (first release date, current version date, version, price, rating count, ratings per day) for a specific resource (App Store ids in one store), which is far more than the title 'Competitor facts' conveys. It does not, however, contrast itself with nearby siblings such as get_ratings or get_overview, so the agent must infer the boundary itself.

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?

It tells the agent where the ids come from ('competitors from get_board'), that the tool is per-store, and that Google Play yields an empty list — effectively a when-not condition. It also gives interpretive guidance ('a fresh update and high ratings/day mean an active rival'). It stops short of naming an alternative tool for Google Play data or for rating history.

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