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

Annotations declare readOnlyHint=false and openWorldHint=true; the description is consistent and adds real value beyond them by disclosing that this call mutates account state (adds the site) and that external DNS visibility can lag by minutes. It does not describe what a not-yet-visible or failed check returns, which is the main remaining gap.

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, front-loaded with the action and its effect, plus one genuinely useful operational caveat. No filler, though the 'record or file' phrasing costs a little precision.

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 and a mutating tool, an agent still cannot tell what the response distinguishes (verified vs pending vs failed) or what to do on failure. The sequencing and DNS-timing context helps, but the result semantics are left entirely unspecified.

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?

Only one parameter and schema coverage is 100%, with the schema itself specifying the domain format (example.com). The description refers to 'the site' but adds no format or constraint detail beyond the schema, 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 (checks) and resource (the record/file from mttr_claim) and distinguishes itself from the sibling mttr_claim by naming it as the prerequisite step. The additional outcome clause (adds the site to the person's account) makes the effect concrete. It falls short of 5 only because 'the record or file' is vague about what artifact is actually being validated.

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?

Implicitly establishes the workflow: call this after mttr_claim has produced a record/file, and the DNS propagation note tells the agent to expect delay and possibly retry. There are no explicit exclusions or failure-path guidance, so it stops short of a fully prescriptive 5.

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