claim_domain

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

With no annotations provided, the description carries the behavioral burden. It discloses the email confirmation requirement, the 30-day reaping risk, and the fact that the name is registered on this account. It also explicitly states the return values (fqdn and optional created record), which is valuable for an agent.

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 compact and front-loaded: it states the core action, key prerequisites, consequences, and return behavior in three sentences. Each sentence adds necessary information and there is no filler.

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?

Given 6 parameters, no annotations, and no output schema, the description is quite complete: it explains first-time email requirements, the 30-day reaping policy, available domains via schema, and what is returned. It could additionally guide the agent toward add_dns_record for subsequent records or check_availability for pre-checking, but that is not a major gap.

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?

The schema already covers 100% of the parameters with detailed descriptions, so the baseline is 3. The description adds context by mentioning the email requirement and registration flow, but it does not add much meaning beyond what the schema already documents for each parameter.

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 and resource: 'Register a subdomain (label.makes.fyi or label.agentdomains.co)', and clearly explains that it can optionally create the first DNS record in the same call. This distinguishes it from related DNA record tools like add_dns_record.

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 gives clear usage context: email is required on first registration, and you can either pass email here or call attach_email first. It also communicates the default domain and when to specify domain. It does not explicitly contrast this tool against alternatives like check_availability or add_dns_record, but it names a relevant sibling for the email prerequisite.

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