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

Annotations only declare readOnlyHint=false; the description adds meaningful behavior by explaining that the tool previews until confirm is true and returns DNS records to add. It does not describe post-confirm side effects or verification requirements, but the key mutation-gating behavior is disclosed.

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 a single front-loaded sentence with no wasted text. The confirm-gating detail is parenthetically placed after the core action and result.

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 appropriately mentions the return value ('DNS records to add') and the confirm-gated workflow. It is nearly complete for invocation, though it could say more about hostname expectations or what happens after confirmation.

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 50%: confirm is fully described in the schema, while the required hostname parameter has no schema description. The tool description does not compensate by explaining hostname format, source, or validation beyond the vague 'custom domain' phrasing.

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 states a specific verb ('Connect'), resource ('custom domain'), and target ('the coach's public page'), which distinguishes it from the gym-domain sibling. It also states the immediate result: DNS records to add.

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 confirm-gated preview behavior gives useful invocation guidance, but the description does not say when to use this instead of get_my_custom_domain, refresh_my_custom_domain, or remove_my_custom_domain. Usage is implied by the connect operation itself rather than explicitly contrasted with alternatives.

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