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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely new behavioral context: the demo is hard-scoped to a single advertiser (page_id 116482854782233) and ad listings expose only approved public creatives. That scoping caveat is the kind of thing an agent cannot get from the schema or 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?

Three sentences, but the ordering is inverted: two sentences of demo caveats precede the one sentence that actually says what the tool does. Front-loading the purpose statement would let an agent classify the tool faster, and the demo scope is stated twice (once in prose, once in the schema enum).

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 characterizes the return value as tracked advertisers with string page_id values, and the demo scoping tells the agent what data is reachable. What remains missing is the relationship to the sibling list/check/search tools.

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% and the single `project` parameter already carries its own enum description ('Only all is available in the public demo'). The description adds no syntax or formatting detail beyond restating that page_id values are strings, so the schema does the heavy lifting.

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 final sentence gives a specific verb and resource: 'List your actively tracked advertisers and their string page_id values.' That is unambiguous on its own, but it never distinguishes itself from the near-named siblings check_brands_tracked and search_tracked_brands, so an agent still has to guess which of the three to call.

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?

There is no statement of when to use this versus check_brands_tracked, search_tracked_brands, or list_brand_ads. The description only asserts what the tool returns, leaving the selection decision entirely to inference from sibling names.

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