meta_ads_audiences_get

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It clearly states 'Read-only,' lists the exact return fields, and notes conditional fields (rule for rule-based, pixel_id for WEBSITE audiences), giving the agent a complete picture of expected behavior without requiring an output schema.

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, front-loaded with purpose, then return fields, then usage guidance. Every sentence provides necessary information with no redundancy. The structure flows logically and stays appropriately concise for the tool's complexity.

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's simplicity (2 params, no output schema, no annotations), the description covers all critical aspects: purpose, output fields including conditional ones, read-only safety, and when to invoke it. It is fully self-sufficient for an agent to select and use 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?

Schema coverage is 100%, so the baseline is 3. The description does not add new parameter-level semantics beyond what the schema provides, but the schema itself already documents account_id's format/fallback and audience_id's source. The description's mention of 'single Custom Audience' reinforces the audience_id purpose but adds no new details.

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 ('Fetches') and identifies the resource ('full detail record for a single Custom Audience'), clearly distinguishing it from sibling list or delete tools. It further specifies the content ('rule definition and approximate_count'), making the tool's purpose explicit 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?

Explicitly states when to use this tool: 'Call this before meta_ads_audiences_delete or before create_lookalike to verify you have the right audience.' This provides direct contextual guidance and differentiates it from alternatives, which is exemplary.

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