Advertiser Search

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

Annotations mark readOnlyHint=false, openWorldHint=true, idempotentHint=false, so the safety profile is partly covered; the description adds meaningful context beyond them by disclosing paid credit consumption, the confirm=true requirement, and that this read-like POST does not publish to social platforms. No contradiction with annotations.

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?

Four sentences, front-loaded with purpose then result then calling guidance then cost/safety caveats. Each sentence earns its place, though the region-default sentence partly duplicates the schema's region description.

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 steps in to describe the return payload (name, advertiser_id, region, associated domains), and it covers the credit/confirm gating that governs correct invocation. Nothing essential for a correct call is missing.

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 schema already documents query, region, account, and confirm. The description reinforces the region default and confirm requirement but adds no syntax or format detail beyond what the schema states, so baseline 3 applies.

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?

States a specific verb (searches) plus resource (Google Ad Transparency Library / advertisers by name) and clearly distinguishes itself from sibling tools like google_ad_library_company_ads and google_ad_library_ad_details by positioning itself as the entry point that yields advertiser_id.

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?

Explicitly tells the agent what to do with the result (use advertiser_id to look up a company's ads) and gives a concrete rule for region handling with examples. It doesn't name the sibling alternative explicitly, but the routing intent is unambiguous.

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