start_domain_verification

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

With no annotations provided, the description carries the full disclosure burden. It discloses that the tool creates a verification record, returns DNS/HTTP instructions, requires Proof account access, and is not opened by start_login. This is substantial behavioral transparency, though it could go further by noting idempotency, failure modes, or existing-domain-verification conflicts.

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 tight and front-loaded: the core action appears in the first sentence, followed by the key outcome and access requirements. 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?

For a simple three-parameter tool with no output schema, the description covers the essential invocation context: what it does, what it returns, and what credentials are needed. It does not explain how to follow up or interpret the returned instructions in detail, but that is reasonably delegated to sibling check/wait tools.

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?

The input schema already covers all three parameters with descriptions, so schema coverage is 100%. The description adds only slight value by tying the verification_method enum to 'DNS/HTTP instructions' and clarifying the B2B context for customer_id. This matches the baseline for high schema coverage.

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 action: 'Start a B2B domain verification' and specifies that it creates a verification record and returns DNS/HTTP instructions. This distinguishes it from many siblings, though it does not explicitly differentiate itself from closely related tools like verify_domain or create_verification.

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 gives explicit access prerequisites: a Proof account and PROOF_API_KEY must be set, with a restart and retry instruction. It also warns that start_login does NOT open this tool, which provides a useful exclusion against a plausible alternative. It does not, however, discuss when to choose this over other verification-related siblings.

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