List Ads

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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the read-only nature is covered. The description adds the constraint that exactly one of three IDs must be provided, and mentions pagination via 'after' and 'limit', which is useful. However, it does not describe output format (markdown/json) or default behavior when status_filter is omitted, leaving some behavioral ambiguity. Given annotations cover safety, a 3 is appropriate.

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 description is concise, with a clear opening statement followed by a structured list of parameters and a final constraint line. It avoids redundancy and is easily scannable. The only minor inefficiency is repeating 'optional' for most parameters, but it remains well-organized.

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 list tool with sparse schema descriptions and no output schema, the description covers the essential invocation details: scoping, status filtering, pagination, and the requirement to provide one of three IDs. It misses mentioning the response_format parameter (though the schema covers it) and does not state default status behavior, but these are minor. The description is sufficiently complete for an agent to call the tool correctly.

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?

The description explains six of seven parameters (excluding response_format) with meaningful details: it clarifies adset_id, campaign_id, and ad_account_id as filters, explains status_filter values, and notes limit's default (20) and 'after' as a pagination cursor. This compensates for the schema's low coverage (14%), though response_format is only documented in the schema. Overall, it adds substantial semantic value beyond the raw 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 clearly states 'Lists ads for an ad set, campaign, or ad account' with a specific verb and resource, and distinguishes itself from sibling tools like meta_list_adsets or meta_list_campaigns by focusing on ads. It also enumerates the three scoping options, making its purpose unambiguous.

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?

The description explicitly instructs the agent to provide one of adset_id, campaign_id, or ad_account_id, which is essential usage guidance. It also implies when to use it (when listing ads) but does not mention alternatives or when not to use it (e.g., for fetching a single ad via meta_get_ad). It gives clear usage rules but lacks exclusionary context.

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