add_domain

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It does mention the authentication requirement, which is useful, but it does not disclose that adding a domain is a state-changing write operation, whether it triggers any verification workflow, what side effects occur, or what the tool returns. For a mutation tool with no annotations, this is insufficient.

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 short, front-loaded with the core purpose, and the ACCESS block provides necessary authentication context in a separate labeled paragraph. Every sentence earns its place with no redundant 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?

The schema covers parameters and the description covers access, but the tool has no output schema and is part of a multi-step verification domain flow. The description does not explain what happens after adding the domain, what response to expect, or what the next recommended step is. This leaves an agent without enough context for a complete invocation or follow-up.

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 all three parameters. The description's phrase 'email sending intent' adds a bit of interpretive context for for_email_sending and 'verification method' maps directly to verification_method, but it does not add meaningful detail beyond the schema. 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 the verb and resource: 'Add a new domain to verify ownership.' It also mentions the optional email-sending intent and verification method. It does not explicitly differentiate itself from sibling tools like verify_domain or start_domain_verification, but 'add a new domain' is specific enough to establish its role.

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 access prerequisites: a Proof account, PROOF_API_KEY, or signing in via start_login. However, it does not explain when to use this tool versus alternatives, such as after adding a domain then using verify_domain, or avoiding add_domain if the domain already exists. Usage is implied by 'add a new domain' but not explicitly routed.

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