claim_vanity_subdomain

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

With no annotations, the description carries the full burden of behavioral disclosure. It explicitly states the claim takes effect immediately and that the address serves the user's public vault as soon as the call returns. It also discloses naming constraints and the Pro account limit, which are behavioral factors. It does not cover error cases (e.g., duplicate claim) or reversibility, but the given information is substantial.

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 well-structured: first sentence states the purpose, second explains the immediate effect, third gives naming constraints, and fourth covers the account limit. Every sentence adds relevant information without redundancy or fluff.

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 the tool's moderate complexity and the presence of an output schema (which covers return values), the description is reasonably complete. It explains the action, the effect, validation rules, and account limitations. It does not detail error handling or prerequisites like authentication, but these are likely conveyed in API errors or are implicit. Overall, it provides sufficient context for effective use.

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 input schema already provides descriptions for both parameters (desired_name and base_domain) with 100% coverage, so the baseline is 3. The description adds meaningful details beyond the schema: the accepted character set and length range for desired_name, and the example 'nova' reinforces the expected format. It also explains that every subdomain serves the full vault, which clarifies the impact of the desired_name 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 clearly states a specific action (claim a vanity subdomain) with a concrete example (nova.vault.cool) and the resource affected (the user's vault). It is distinct from sibling tools, none of which deal with subdomains, so it is unambiguous.

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 implies when to use this tool (to obtain a vanity subdomain for the vault) and provides constraints that guide usage: naming rules (lowercase letters, digits, hyphens, 2–63 characters) and the Pro account limit of 10 subdomains. It does not explicitly mention alternatives or exclusions, but no obvious alternative exists among siblings. The context is clear enough for an agent to decide appropriately.

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