get_custom_audiences

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

No annotations are provided, so the description carries the disclosure burden. It does disclose the read-only nature via 'List', documents pagination cursors, available fields with defaults, and the return shape. However, it omits permission requirements, error behavior, and any caveats about pagination or result limits.

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 purpose is front-loaded in the first sentence, and the argument documentation is organized into a clean, scannable list with defaults and return information. There is no filler or redundant restatement of the tool name.

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 read-only list tool with 5 parameters and an output schema, the description covers the operation, all parameter meanings, defaults, and the return value. It is missing only explicit routing guidance relative to sibling audience-related tools and any behavioral caveats.

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 0%, so the description must fully compensate. It does: act_id is given with an example, fields are enumerated with a default list, limit is defined, and after/before are described as forward and backward pagination cursors. Every parameter receives meaningful semantic context.

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 names a specific verb and resource: 'List all custom audiences for an ad account', and gives illustrative categories like CRM uploads, pixel-based, and lookalikes. It is clear about scope, but it does not explicitly distinguish itself from sibling tools such as get_saved_audiences, leaving some ambiguity among audience-related tools.

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 guidance on when to use this tool versus alternatives like get_saved_audiences or get_pixels, and no stated exclusions or prerequisites. The description focuses entirely on arguments and return value, so it provides no decision support for tool selection.

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