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

Goes well beyond the annotations by disclosing the account-token requirement, the Stripe payment flow, what owner info is collected, the post-payment outcome (registration, HTTPS, no DNS settings), the claim-first ordering, and critically that it does not charge a card. This is exactly the behavioral context annotations can't carry.

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?

Five sentences, but each adds distinct value, and the auth prerequisite is front-loaded in parentheses. Slightly long, yet nothing is clearly redundant.

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 still explains what is returned (a payment link) and the full downstream flow. Auth, prerequisites, and post-conditions are all covered for a mutation-style tool.

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 name, site, and extras are already documented in the schema. The description adds flow context but no per-parameter meaning beyond what the schema provides, making the baseline 3 appropriate.

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 — returns a payment link to register a domain and attach it to a site. This clearly separates it from siblings like get_email_checkout_link, connect_domain, and claim_site.

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?

Gives clear context: use it to register a domain and put it on an account's site, and notes that for a site not yet on the account the claim happens first. It does not explicitly contrast with alternatives such as connect_domain or point_domain, so the when-not guidance is left to inference.

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