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

The description adds useful behavioral context beyond the annotations: it identifies the external DNS check and the authentication/subscription requirement. It is consistent with the idempotentHint and destructiveHint annotations, and no contradiction is present. It does not describe failure behavior if the TXT record is absent, but the annotations already cover the core safety profile.

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 concise sentences with no wasted words. The core action and mechanism are front-loaded, and the authentication requirement is stated efficiently.

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?

The description covers the action, authentication, and mechanism, and the output schema handles return-value documentation. However, it omits the important workflow context that a verification token/TXT record must already exist before calling this tool, which is a notable gap for an agent deciding how to proceed.

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 both 'domain' and 'response_format' are already adequately documented in the schema. The description does not add parameter-level meaning beyond the schema, so the baseline score of 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 clearly states the action ('Complete domain verification') and the specific mechanism ('checking the expected HIBP TXT record on the target domain'). It is easily distinguished from the sibling generate_domain_verification_dns_token, which creates the token rather than verifying it.

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?

The description provides a clear prerequisite ('Requires an authenticated subscription with domain-verification access') and implies that this is the verification step after a token has been generated. However, it does not explicitly name the sibling tool for generating the token or explain the DNS-record prerequisite, leaving the workflow ordering to inference.

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