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

With no annotations provided, the description carries the full behavioral burden. It usefully states that no outreach happens here and that the audience can be attached later, but it does not disclose whether saving is idempotent, whether an existing name is overwritten, or what the response contains.

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 short sentences, all useful and front-loaded. The core action is stated first, the relationship to search_audience is second, and the non-outreach reassurance is last. No filler is present.

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?

The tool is simple, but there is no output schema and no annotation coverage. The description covers purpose and side-effect boundaries, yet it leaves parameter semantics to be inferred from search_audience and does not mention what the tool returns, which an agent would need to confirm success.

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 compensate. It tells the agent that the filters come from the same filter set as search_audience and that the audience is named, but it does not explain the individual filter fields or that only 'filters' is required while 'name' is optional.

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 and resource ('Save a searchable audience') and immediately distinguishes this tool from its sibling search_audience by noting it uses the same filter set but persists the audience. It also clarifies that no outreach happens here, which prevents confusion with campaign-launch 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?

The description explains that the saved audience can later be attached to a campaign and explicitly references search_audience as the source of the filter semantics. It does not fully enumerate when not to use this tool versus other audience-related siblings, but the context is clear enough for an agent to route correctly.

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