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

With no annotations provided, the description carries the behavioral disclosure burden and largely satisfies it: states returned counts and global exposure, explicitly says no standalone creative/ad IDs are returned, caps the date range at 180 days, and clarifies non-obvious country-filter semantics. It omits pagination/rate-limit details, but nothing here suggests mutating behavior.

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 four short, purposeful sentences with no fluff: purpose and scope, returned metrics, country-selection caveat, and constraint warning. Each sentence earns its place and the most defining information is front-loaded.

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?

Since there is no output schema, the description compensates by naming the returned metrics and clearly stating the no-ID caveat. Parameter schemas already cover required fields and formats, and the description adds the non-obvious behavioral constraints that are needed to invoke this tool correctly. The picture is complete for an agent.

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 baseline is already solid. The description adds value beyond the schema by clarifying that game_ids must supply 2-5 tokens, the games share the same date range, and country_code alters the target list rather than representing geographic exposure or preference. It could more explicitly map rank_by values to the named metrics, but it substantially supplements the schema.

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 identifies a specific action and resource: compare 2-5 games under shared date-range, deduplication, and metric definitions, and it lists exact returned metrics. The cardinality '2-5' plus the cross-game comparison framing clearly distinguishes it from the many single-tool get_* siblings in the list.

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 scopes the tool to multi-game comparison with identical date range/dedup/metrics and warns that country filtering means target-list inclusion, not geographic exposure or preference. It does not explicitly name alternative tools for cases such as needing standalone creative IDs or geographic exposure, but the intended use context is clearly implied.

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