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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so safety is covered. The description adds the useful behavior that region/city keys are meant to be dropped into adset_settings.regions / cities, but says nothing about result shape, pagination, or result limits for a lookup tool.

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 opening clause ('Find Meta targeting by name: ...') and the second sentence ('Search Meta targeting: ...') largely restate the same category list, so the description duplicates itself. The useful integration hint is present but buried at the end.

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 two-parameter read-only lookup with no output schema, the description covers purpose and the downstream key usage, which is the essential part. It still leaves the agent guessing which fields come back and how this differs from list_targeting.

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 only 50%: 'q' is documented but 'type' has no description beyond its enum. The description compensates by explaining that 'locations' covers regions and cities, and that locales mean languages, plus that the returned key is what goes into adset_settings — real meaning 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 uses a specific verb and resource ('Find / Search Meta targeting') and enumerates the searchable categories (countries, regions, cities, interests, behaviors, languages). It does not, however, distinguish this tool from the sibling 'list_targeting', which an agent could easily confuse with it.

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?

It gives useful downstream context — 'Use the ids / keys in prepare_launch adset_settings' — which tells the agent why it would call this. But it never states when to prefer this over the sibling list_targeting, nor any exclusions or prerequisites.

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