Register Domain

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

The description fully discloses the irreversible financial nature and asynchronous behavior, which annotations (readOnlyHint: false, openWorldHint: true, idempotentHint: false) do not capture. No contradiction with annotations.

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 lengthy but well-structured: purpose first, then warnings, async note, and instructions. All sentences are necessary and concise given the complexity of the tool.

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 complexity (5 parameters, nested objects, no output schema), the description covers essential context: asynchronous operation with operationId, required pre-checks, and user confirmation. It is complete enough for correct agent invocation.

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 coverage is 100% with descriptions for all 5 parameters. The description adds marginal value by noting that contacts require prior creation via save_contact, but this is already implied in the schema's contact descriptions. Thus baseline 3 is 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?

The description clearly states 'Register a new domain name' as the primary action. It distinguishes this tool from siblings like transfer_domain, renew_domain, and restore_domain by specifying it's for new registrations and includes warnings about financial and irreversible nature.

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 guidance is provided: use check_domain_availability first, always confirm with user before calling, and poll with get_async_operation for completion. It also warns about the financial commitment, leaving no ambiguity about when and how to use this tool.

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