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

Annotations already establish that this is a read-only, idempotent, non-destructive, closed-world operation. The description adds useful behavioral context: it aggregates across every channel the brand watches and counts every ad on record unless startedWithinDays or activeOnly narrows the scope.

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 two tight sentences with no wasted language. It front-loads the aggregate purpose and then immediately states the default scoping behavior of the filters.

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 an output schema present, the description need not explain return values, and the annotations already carry safety and idempotency semantics. The description supplies the essential conceptual model — aggregate competitor creative mix across channels, with optional filters narrowing the ad set — which is sufficient to invoke the tool correctly.

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 high at 80%, so most parameter meaning is already documented in the schema. The description reinforces the default counting behavior and names startedWithinDays and activeOnly as narrowing filters, but it does not add meaning for brandId, channel, or competitorId beyond what the schema provides.

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 states a specific retrieval and aggregation operation: the creative mix of a brand's competitors across watched ad channels, broken down by formats, media types, platforms, CTAs, and creative features. It is clearly distinct from list-oriented siblings like list_competitor_ads and from the individual-analysis-oriented get_competitor_analyses.

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 phrase 'in aggregate' implies this is for aggregate competitor creative reporting rather than a list of individual ads, which gives some usage context. However, the description never explicitly names alternatives or states when to choose this tool versus list_competitor_ads, get_competitor_analyses, or get_competitor_audience, leaving selection to inference.

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