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

Annotations already declare the safety profile (mutation, idempotent, non-destructive, closed-world). The description adds genuinely useful context beyond that: account-token auth requirement, a single-claim constraint, the 'not already on another account' restriction, and 'Does not charge.' Return behavior is not described, but that is minor for this tool.

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?

Roughly three sentences with no filler; the auth requirement leads and the action follows immediately. The leading parenthetical is slightly awkward but front-loads a critical prerequisite.

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 single-parameter mutation tool with full schema coverage and rich annotations, the description covers auth, the single-use constraint, eligibility, and the no-charge fact. No output schema exists, and the description does not explain the response, but it is complete enough to invoke 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 description coverage is 100%, so the claim_url parameter and its 'full link or code after the #' format are already documented. The description's mention that the link 'ends with # and a code' reinforces but does not substantially extend the schema. 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: 'Attaches an unclaimed site to this account using its claim link.' Claiming is naturally distinct from siblings like connect_domain or transfer_domain_out. It is clear and specific, though it does not explicitly name or differentiate against any sibling tool.

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?

Provides clear preconditions: a valid account token, an unclaimed site, a claim link, and 'not a site already on another account.' This tells the agent when the tool is applicable. It stops short of naming an alternative tool for related scenarios.

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