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

Annotations already declare readOnlyHint/idempotentHint, so the trailing 'Read-only' is redundant, but the description adds real behavioral context beyond them: the ambiguous country-name matching against postal codes and the fact that a valid location id does not imply ad eligibility under OpenAI policy. That is genuinely useful pre-call knowledge.

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 the purpose and the chaining target, then caveats. Dense but each sentence carries information; the only waste is restating 'Read-only' already covered by annotations.

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-value documentation is not strictly required, yet the description still usefully sketches the returned fields for chaining. It covers the ambiguity and policy gotchas an agent needs; only the limit/account parameters remain unexplained.

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 0%, so the description must carry the param burden. It does explain the query parameter well (English/local names, ISO codes like TR), but says nothing about the limit or account parameters, leaving two of three undocumented in both schema and description.

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 (finds) and resource (ChatGPT Ads location ids) plus the enumerated location types. It is clearly distinguishable from the many sibling geo tools (geo_target_search, microsoft_location_search, tiktok_region_search) by naming the ChatGPT Ads platform explicitly.

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 names the downstream consumption path (pass the id or ISO code to update_chatgpt_ads_campaign include_locations/exclude_locations), tells the agent what input forms work (English or local name, ISO code), and warns about the postal-code false-match and the pilot-country/category-policy caveat. When-to-use and when-not-to-trust are both covered.

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