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

Annotations already declare readOnlyHint=true, covering the read-only safety profile. The description adds that domains are returned with verification status and that team scoping changes the endpoint, but it does not disclose response shape or pagination behavior.

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?

Two short sentences with no filler. The main capability is front-loaded, and the endpoint note provides useful API mapping without bloating the description.

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 read-only annotation, full parameter coverage, and straightforward list operation, the description supplies enough information to select and invoke the tool. It names the resource, scope, endpoint variants, and verification-status output. It could mention the paginated response shape, but the schema's cursor and per_page parameters already signal pagination.

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 all four parameters are already documented. The description adds only account-versus-team context and endpoint mapping, which does not materially go beyond the schema. Baseline 3 is appropriate.

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 ('List'), names the resource ('custom domains'), and clarifies scope ('account (or a team)'). It also notes that results include verification status, which distinguishes it from sibling list_* tools targeting other resources.

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 provides clear context for account-level versus team-scoped usage, including the teamId endpoint variant. It does not explicitly state when not to use it or name an alternative, but no sibling tool duplicates the domains resource, so selection is straightforward.

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