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

Annotations already establish read-only, idempotent, non-destructive behavior. The description adds useful context beyond annotations by noting the sub-account key requirement and clarifying that the tool does not create or verify domains, though it does not discuss pagination or response shape.

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 compact sentences with no waste. The access mode and purpose are front-loaded, and the exclusion follows immediately.

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 list/audit operation with rich annotations and no output schema, the description is largely complete: it covers the domain-audit scope, DNS/verification visibility, auth context, and mutation exclusions. Minor gaps remain around the search parameter and exact returned fields.

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 coverage is 67%, with limit and offset documented in the schema but search left undocumented. The description adds no parameter-level meaning, so it neither helps interpret search nor supplements the pagination parameters.

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 audit/list purpose for sending domains and adds scope around DNS record configuration and verification failures. It clearly distinguishes from create/verify operations, though it does not explicitly contrast with the sibling get_domain tool for single-domain retrieval.

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?

It gives clear context by labeling the operation as READ and specifying sub-account key authentication, and it explicitly excludes create/verify use cases. However, it does not name an alternative tool or explain when to use get_domain instead of this list tool.

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