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

Annotations only say non-readonly, non-idempotent, non-destructive; the description adds substantial context beyond that: the token expires, the claim_secret is shown only once and must stay private, only the verification snippet is published, and existing keys remain valid until fresh proof succeeds. It also declares that no backlink is required and enumerates the supported proof methods (DNS, meta tag, well-known file), which is real behavioral disclosure for a one-shot mutation.

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 sentences, each carrying a distinct payload: purpose, return values and secrecy rule, next-step call, and the non-requirements. Nothing is repeated from the schema or annotations, and the operational facts are front-loaded.

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 single-parameter mutation with an output schema present, the description supplies everything an agent needs: purpose, the secret-handling obligation, the exact follow-up call with its arguments, and the guarantee that existing keys are unaffected. Return-value structure is left to the output schema, which is the right division of labor.

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?

There is a single required parameter whose schema description is already complete ('A domain name such as example.com (no scheme, no path)'), so the schema carries the parameter semantics. The description only reinforces that the domain must be one you control, adding no further format or constraint detail.

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?

Opens with a specific verb+resource ('Start optional ownership management or recovery for a domain you control'), which is a distinct purpose from sibling reads like lookup_domain or verify_domain. It also positions itself in the workflow by naming verify_domain as the follow-up step, so an agent can tell it apart from the rest of the domain tools.

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 gives clear context for when to use it (ownership management or recovery on a domain you control) and explicitly directs the agent to the next call: 'call verify_domain with claim_id and claim_secret'. It does not mention exclusions versus siblings such as rotate_owner_key or register_domain, so it stops short of full when-not guidance.

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