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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds modest workflow context by stating the output is valid targeting IDs for create_x_ad_draft, but does not describe result format, pagination, or other behavioral details.

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?

Two sentences with no filler. The core action and the workflow context are front-loaded, and every word contributes to selecting and invoking the tool correctly.

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 low-complexity, read-only lookup tool with comprehensive schema and annotations, the description is mostly sufficient. It explains the purpose, when to use it, and the output purpose, though it does not explicitly describe the result structure since there is no output schema.

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 applies and the schema already explains query, companyId, and kind. The description's reference to 'interests or locations' corroborates the kind parameter but adds no new semantic detail beyond 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 clearly states the tool searches X Ads targeting by interests or locations, and ties it to producing valid targeting IDs for create_x_ad_draft. It is specific about verb and resource, but it does not explicitly differentiate from the sibling tool search_ad_targeting.

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 'Use when designing an X ad draft and you need valid targeting ids' gives a clear context for when to invoke the tool. It does not mention when not to use it or name alternatives like search_ad_targeting, so it stops short of full exclusion guidance.

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