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

The description usefully discloses the confirm-gated preview behavior, which matters given readOnlyHint=false — an agent learns the default call is a dry run. However, it does not say what the confirmed call actually mutates (re-triggering DNS verification? SSL re-issuance? rate limits on repeated refreshes?), so the mutation profile remains opaque beyond the annotation.

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 compact clauses, front-loaded with the action and resource, with the confirm-gate note parenthesized where it doesn't obstruct scanning. Nothing is wasted.

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 one-parameter tool with no output schema, the description covers what it does and how to actually execute it. The gap is the missing disambiguation from the get_/connect_ custom-domain siblings and the absence of any note on what the re-check can change.

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?

Single parameter with 100% schema description coverage; the schema already explains that confirm must be true to execute. The description restates that behavior without adding format, cost, or side-effect details, so 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?

Specific verb + resource: 'Re-check DNS/SSL status of the coach's custom domain.' The possessive 'coach's' implicitly separates it from refresh_gym_custom_domain, but it never names get_my_custom_domain or connect_my_custom_domain, so an agent must infer the boundary from the name alone.

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?

No statement of when to call this versus get_my_custom_domain (status read) or connect_my_custom_domain (initial setup), and no preconditions such as 'domain must already be connected.' The only guidance present is the confirm-gate mechanics, which is execution mechanics rather than tool selection.

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