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

Beyond the annotations it adds real behavioral context: a DNS record is returned, activation is conditional on record propagation plus certificate issuance, and repeat calls serve as a progress check. It omits failure/timeout behavior and roughly how long issuance takes, which would round out the picture.

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?

Three tight sentences, front-loaded with the action, then the return/handoff, then the polling pattern. No filler; each sentence carries a distinct fact.

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 properly discloses the return value (the DNS record) and the completion condition. It leaves the response shape for pending state and error reporting unspecified, but an agent has enough to call and poll correctly.

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 100% — both 'site' and 'domain' are documented with examples in the schema, including the site-address-or-id convention. The description's example domain ('www.myapp.com') repeats the schema example and adds no new parameter information, 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?

States a specific verb and resource ('serve one of your sites on your own domain') and gives a concrete example plus plan gating. It's unmistakable what the tool does, but it doesn't explicitly contrast with update_site or other site-mutation siblings.

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?

Clearly conveys the usage flow: call it, add the returned DNS record, and call again with the same domain to poll until the certificate is issued. It doesn't name alternatives or state when not to use it, but the context for invoking it is clear.

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