listDomains

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

No annotations are provided, so the description must carry the burden of behavioral disclosure. 'List' implies a read-only operation, and the description clarifies the active-domain scope. However, it does not mention pagination, response format, required authentication, or the meaning of 'active,' leaving some behavioral details to the linked API reference.

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 with no wasted words. The core action is front-loaded, the optional filter is stated clearly, and the API reference link is a useful addition without clutter. Every element contributes to understanding.

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 simple tool with one optional parameter and no output schema, the description covers the essential invocation context: what it lists and how to filter. It does not describe return values or pagination, but the API reference link compensates, and the absence of required parameters keeps the call straightforward.

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?

The schema provides 100% coverage of the only parameter, 'portfolio,' with a description already explaining it as a filter. The tool description adds 'Optionally filter by portfolio,' reinforcing optionality but adding little beyond the schema. Baseline 3 applies because the schema handles the semantic load.

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 states a specific verb and resource: 'List active domains in the account.' The word 'active' distinguishes it from the sibling listExpiringDomains and other domain-related tools, so an agent can identify the correct tool without needing to infer.

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 provides clear context: the tool lists active domains account-wide and optionally filters by portfolio. It does not explicitly name alternatives or exclusion conditions, but the scope is unambiguous and the optional filter is stated, giving an agent enough direction on when to use it.

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