create_custom_audience

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

With no annotations provided, the description carries the full burden of disclosing behavior. It only states the action 'create' and mentions subtype, but does not disclose side effects, required permissions, or any prerequisites. For a mutation tool, this lacks essential behavioral context.

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 two sentences, front-loaded with the primary action and followed by a concise explanation of the subtype parameter. Every word is relevant and there is no redundancy.

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 has four parameters and no output schema, the description is incomplete. It does not explain what the tool returns, which subtypes require additional parameters like customer_file_source, or how this fits with related tools such as create_lookalike_audience. More context is needed for an agent to use it effectively.

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 100%, so the baseline is 3. The description adds value by explaining that subtype determines the audience source and listing examples, which clarifies the role of this parameter beyond the schema's enum list.

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 creates a new custom audience with a specific verb and resource. It mentions subtype as a key differentiator, but does not explicitly distinguish from the sibling tool create_lookalike_audience, which could cause ambiguity since LOOKALIKE appears as a subtype.

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 that subtype determines the audience source, giving some context on how to use the tool. However, it does not provide explicit when-to-use vs alternatives or any exclusions, leaving room for interpretation.

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