Company Ads

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

Goes beyond annotations by disclosing the credit cost model, the required confirm=true gate, and what the response contains at each cost tier. It also clarifies that read-like POSTs do not publish to social platforms, resolving the apparent tension with readOnlyHint=false. No rate-limit or failure behavior is described, but the cost/auth disclosure is substantive.

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?

Three sentences, front-loaded with purpose then cost/return semantics then safety note. The enumerated return-field list is slightly long but each item is informative and no sentence is redundant.

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 usefully enumerates return fields and states the cost/confirmation contract, which is what an agent needs before committing credits. Pagination via cursor and the political-topic/region coupling are left to the schema, which documents them adequately.

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 100%, so the baseline is 3; the description earns above that by explaining what get_ad_details actually changes in the returned payload and tying credit cost to the parameter choice, which the schema description only states as 'Will cost 25 credits.'

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 (fetches), resource (public ads for a company), and data source (Google Ad Transparency Library), plus the two lookup keys (domain or advertiser_id). This clearly separates it from google_ad_library_ad_details and google_ad_library_advertiser_search.

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?

Explains the key cost tradeoff that governs selection: get_ad_details=true costs 25 credits and returns rich fields, while omitting it returns only advertiserId and creativeId at 1 credit. It does not, however, explicitly route the agent between this tool and the sibling google_ad_library_advertiser_search or ad_details tools.

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