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

Despite annotations covering safety and idempotency, the description adds rich behavioral detail: it returns TXT record values (challenge_name, challenge_token), explains that fline checks automatically for 48 hours, and notes that check_domain checks immediately. This goes well beyond the structured 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 dense but front-loaded, starting with the core action and following with return values, verification process, and guidance. Every sentence contributes useful information without redundancy.

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 and low parameter documentation, the description does a good job explaining the expected response and verification flow. However, it omits details about project_id and idempotency_key, which an agent may need to call the tool correctly.

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 0%, so the description must compensate. It gives an example for domain (www.example.com) and implies project context, but it never explains project_id or the optional idempotency_key, leaving two of three parameters semantically unclear.

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 states a specific verb and resource: attaching a web address/domain to a project. It clearly distinguishes this tool from siblings like list_domains, check_domain, and delete_domain by explaining its unique action and outcome.

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?

It provides clear context: prefer a subdomain because most DNS providers allow no CNAME on a bare name, and it references the use_a_web_address prompt. It also names related tools (list_domains, check_domain) and their roles, though it does not explicitly state when not to use this tool versus alternatives.

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