get_ad_performance

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

No annotations are provided, so the description carries the full burden for behavioral disclosure. It only says 'Return' and describes the output content, but it does not mention functional traits like required permissions, data freshness, rate limits, or any caveats. For a 'get' tool this is lower risk, but the lack of operational context is a gap.

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 sentences, directly states the core function, and then lists relevant use cases. Every word adds value, and there is no verbose or redundant content.

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?

An output schema exists, so return values do not need to be explained. The description covers purpose and use cases, which is sufficient for a read-only tool with a simple parameter set. It could be more complete by noting prerequisites or data delivery specifics, but it is adequately contextualized.

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 all three parameters (customer_id, days, login_customer_id) already have clear descriptions. The tool description adds no additional parameter-level meaning, so it lands at the baseline 3.

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 clearly states the tool 'Return ad-level performance including RSA headlines and descriptions.' This specifies both the resource (ad-level performance) and the distinguishing detail (RSA headlines/descriptions), setting it apart from sibling tools like get_campaign_performance or get_keyword_performance.

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 gives explicit use cases: 'creative audits, A/B analysis, and identifying low-performing ad copy that should be refreshed.' This implies when to use it, though it does not explicitly name alternatives or exclusions. That is strong guidance for a performance-focused tool.

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