list_custom_audiences

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

No annotations are provided, so the description carries the full disclosure burden. It discloses pagination and the memberships_revision return field, and 'List' implies a read-only operation. However, it doesn't disclose account scoping (whether ad_account_id is required), authentication needs, or pagination mechanics.

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 short sentenses with no wasted words; the core purpose is front-loaded and each sentence adds distinct information (filters, return field, pagination). Slightly choppy phrasing around 'policy_revision for eligibility' keeps it from top marks.

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 9-parameter list tool with no annotations and no output schema, the description covers core behaviors but leaves ambiguity about account scoping, pagination cursor semantics, and matched_count_granularity. An agent can call it correctly for basic cases but may need to probe for edge details.

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 only 33% (3 of 9 parameters documented), so the description must compensate. It adds meaning for intended_use, ids (mapping to custom_audience_ids), and policy_revision ('for eligibility'), but leaves ad_account_id, the pagination cursors (before/after/limit/order), and matched_count_granularity without explanatory value.

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 states a specific verb and resource ('List custom audiences') and names the filter dimensions (intended_use, ids, policy_revision). It does not explicitly contrast with siblings such as get_custom_audience, but its list/scoping purpose is 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 implies when to use this tool — to list/filter audiences and to obtain membership_revision for later mutations — but provides no explicit exclusions or alternative routing (e.g., 'use get_custom_audience for a single audience'). Guidance is present but left to inference.

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