meta_ads_audiences_list

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

The description explicitly states the tool is 'Read-only,' which is important behavioral info since no annotations are provided. It also notes that 'Approximate counts from Meta may lag actual size by 24–48h,' a helpful data freshness hint. However, it does not mention other potential behaviors like pagination for large result sets or rate limits, which would be useful completeness given no annotation support.

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 at four sentences, each adding unique value: what it does, what it returns, read-only nature, usage guidance, and data freshness caveat. Information is front-loaded with the purpose, and there is no redundant or extraneous content.

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?

Given the tool is a simple list operation with no required parameters and a small number of parameters, the description is fairly complete. It explains return fields and usage. However, it does not mention pagination behavior or how to iterate over many audiences (the limit parameter is present but the description doesn't clarify that multiple calls might be needed). Also, error conditions are not covered, but for a straightforward read-only list tool, this is acceptable.

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 input schema has 100% coverage with clear descriptions, so the baseline is 3. The description adds some value beyond the schema by noting the fallback behavior for account_id ('falls back to META_ADS_ACCOUNT_ID from the configured credentials') and confirming default/max values for limit. These are useful but not critical; the schema already documents the parameter meaning adequately.

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 the tool lists custom audiences in a Meta Ads account, specifies the return fields (id, name, subtype, etc.), and distinguishes itself from other tools by mentioning its typical use case of retrieving audience_id for ad set targeting or lookalike creation. The verb 'Lists' and resource 'Custom Audiences' are specific and 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 provides explicit guidance on when to use this tool: 'Use this to find an audience_id before targeting an ad set (meta_ads_ad_sets_create / update) or before creating a lookalike (audiences.create_lookalike).' This clearly contrasts with those sibling tools. However, it does not explicitly state when not to use it (e.g., when a specific audience's details are needed, the 'get' endpoint would be more appropriate), missing an opportunity to offer exclusion criteria.

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