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

Annotations already declare readOnlyHint=false, idempotentHint=false and destructiveHint=false, so the mutation profile is known. The description adds useful context by disclosing that the call returns DNS records, but says nothing about failure modes, whether domains must be unique per org, or whether attaching an unverified domain has side effects.

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?

A single tight sentence with the action and its return value front-loaded. Nothing superfluous.

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 2-param mutation with no output schema, the description covers what the tool does and hints at the return payload, but omits the verification follow-up and any handling of the returned DNS records. Annotations carry the safety profile, yet the workflow context around domain_verify is missing.

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%, and both parameters (orgId, domain) are documented in the schema including the pointer to org_list. The description adds no further meaning about either parameter, so the baseline 3 applies.

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?

States a specific verb ('Attaches') and resource ('custom domain') and adds the outcome ('returns the DNS records to publish'). The attach/detach/verify name family makes the distinction from siblings self-evident, though no sibling is named explicitly.

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?

Usage is only implied: an agent infers this is the first step of onboarding a new domain. There is no explicit statement of prerequisites, no mention of the follow-on domain_verify step, and no exclusion of domains already attached (which a caller must use domain_list for).

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