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

Annotations already declare idempotentHint=true, destructiveHint=false, and openWorldHint=false, but the description adds genuine context: the operation replaces existing registrant/postal data and the body must be complete because registrar filing consumes it. It does not cover auth/permission requirements, which is a minor gap.

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 short sentences, front-loaded with the operation and followed by the ordering prerequisite and idempotency guarantee. No filler.

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 pure setter with no output schema and full schema coverage, the description supplies the sequencing rule, completeness requirement, and idempotency behavior an agent needs. Only permission/auth context and the safe way to read back the stored profile are unaddressed.

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 every one of the 11 fields, including formats like ISO 3166-1 alpha-2 and the phone country-code convention, is already documented. The description's only parameter note (everything except addressLineTwo is required) merely restates the schema's required array.

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 (creates/replaces the workspace's registrant and postal contact details) and distinguishes itself from read-side get_billing_profile by being the write counterpart. An agent knows exactly what state this mutates without opening the schema.

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?

Explicitly tells the agent to call this before create_dfy_order and explains why (domain registration files these details with the registrar). That is a clear ordering prerequisite, though it does not name a when-not condition or an alternative (e.g., get_billing_profile for reading existing values).

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