list_custom_audiences

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

No annotations provided, so the description carries the full burden. It discloses that the tool flags audiences with issues (unusable, too small, etc.), giving some behavioral insight. However, it does not state whether the operation is read-only, if authentication is needed, or any side effects. The description is adequate but not rich.

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?

Description is succinct: a main paragraph explaining the tool's purpose and features, followed by two short parameter descriptions. Every sentence adds value without redundancy. The key information is front-loaded.

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 tool with 2 parameters and no output schema, the description covers the purpose and arguments. However, it does not describe the return value structure beyond mentioning included diagnostic fields. The agent might need more detail on the output format to use the tool effectively, but it is passable.

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?

Input schema has no descriptions (0% coverage), so the description adds meaningful semantics: it explains account_id with an example ('act_123456789') and clarifies limit as max audiences with a default. This compensates well for the missing schema descriptions.

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?

Description clearly states the tool lists custom audiences for an ad account with additional information like type classification, size estimates, delivery status, and diagnostic warnings. It also flags problematic audiences. This verb+resource combination and the inclusion of diagnostic features distinguish it from sibling listing tools like get_accounts or get_campaigns.

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?

No explicit guidance on when to use this tool versus alternatives. However, the context of listing custom audiences is clear, and sibling tools are for different entities. The agent can infer usage from the domain, but the description lacks explicit when-to-use or when-not-to-use statements.

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