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

Goes well beyond the annotations by disclosing concrete effects and failure modes: it replaces any existing domain (explaining destructiveHint), the domain is not live until DNS records exist and verify_domain succeeds, a paid plan is required, and a domain already bound elsewhere is refused. This is rich operational context an agent could not infer from the schema.

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?

Four front-loaded sentences with zero waste: action, then DNS/verification consequence, then plan gate, then replace/refuse conditions. Each sentence carries distinct, decision-relevant information.

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?

With no output schema, the description still tells the agent it returns DNS records to add, explains the async verification flow, plan constraints, and refusal conditions. An agent has everything needed to call it correctly and set user expectations.

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 100%, so the schema already documents all three parameters including the no-www/no-https guidance. The description adds only the 'domain the user owns' framing, not new syntax or semantics, so 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?

States a specific verb (connect/claim) and resource (a custom domain a user owns) tied to a site. The sibling landscape (remove_domain, verify_domain) is implicitly disambiguated because the description explains this is the *start* of the flow and that verify_domain is a later step.

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?

Gives clear context and prerequisites: paid plan required, free plan refused, and it starts a flow completed by verify_domain. It lacks an explicit 'use remove_domain to detach' style routing, so it falls just short of a full when/when-not statement.

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