Prepare a registrar link (no purchase)

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered; the description reinforces this by explicitly denying registration, payment and reservation, and by disclosing the user-confirmation gate. It stops short of stating whether the returned link expires, is reusable, or how it should be presented to the user.

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 return value and the critical 'never registers/pays/reserves' scope before the calling condition. Every sentence carries a distinct, load-bearing 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 correctly takes on the burden of describing the return value ('a registrar search/checkout link'). Missing only minor operational detail such as link lifetime or whether registrar selection changes the link destination, which is not fatal for a read-only link generator.

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 only 33%, so the description must compensate, and it does so partially: it clarifies the domain scope ('this exact domain') and fully reinforces the userConfirmed=true requirement. However, the optional registrar parameter — including its porkbun/namecheap/cloudflare enum and what happens when it is omitted — is never addressed in either the description or the schema.

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 registrar search/checkout link for a domain' — and pins down the negative scope ('never registers, pays or reserves anything'), which cleanly separates it from a purchase/registration action. An agent can tell instantly this is a link-generation tool, not a transactional one.

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?

Explicit precondition: only call with userConfirmed=true, and only after the user has explicitly asked for a purchase link for this exact domain. That is both a when-to-call rule and a gating condition, leaving nothing to inference.

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