domains_prepare_registration

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

With no annotations, the description carries the full burden and does so thoroughly. It discloses that the tool never executes the registration, that the API has no execute endpoint, and that purchase/renewal/transfer/DNS changes are never executed. It also reveals the return behavior: a safety-checked/validated plan with locked total and fee.

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 somewhat repetitive: 'returns the safety-checked plan only' and 'returns the validated plan only' say the same thing, and 'Show the plan... to the human first' is stated twice. The core message is front-loaded, but several sentences could be merged without losing information.

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 there is no output schema, the description does a good job of explaining what is returned (a plan with locked total and fee) and the critical non-execution behavior. It could be more specific about the plan's structure or next steps after showing it to the human, but the information is sufficient for safe 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?

Schema description coverage is 100%, so the schema already documents both parameters (domain and period). The description adds no additional parameter-specific meaning, only mentioning the locked total and fee which are output concepts rather than parameter semantics.

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 verb and resource: 'Prepare (never execute) a domain registration: returns the safety-checked plan only.' It explicitly contrasts this tool with an execution step and positions it as 'Step 2 of the two-step purchase flow,' which distinguishes it from sibling tools like domains_get_quote and domains_check_availability.

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 provides clear context by identifying this as Step 2 of the purchase flow and instructs the agent to 'Show the plan... to the human first.' It does not explicitly name alternative tools or state when not to use it, but the non-execution warning and two-step framing make the intended context clear.

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