verify_email_otp

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

There are no annotations, so the description carries the burden of behavioral disclosure. It does disclose the access requirement and the conditional outcome ('Completes the add-email flow if the code is correct'), but it does not describe what happens on invalid codes, whether the session is consumed, or any retry/expiry behavior.

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 brief and front-loaded with the primary action, then adds necessary access context in a separate note. Every sentence contributes useful information, and there is no redundant or filler text.

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 two-parameter tool with no output schema, the description gives enough context to call it correctly: it names the operation, the flow it completes, the two required inputs, and the access requirements. It could be more explicit about expected outputs or error cases, but it is largely complete for its complexity.

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%, and both parameters are already described in the schema: code is the OTP received via email, and session_id is the add-email session ID. The description adds no meaning beyond that, so the baseline of 3 applies.

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: 'Submit the OTP code to verify an email addition.' It also clarifies the tool's role in the add-email flow, which distinguishes it from generic verification or 2FA related siblings like verify_2fa and submit_verification_code.

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 clearly ties the tool to completing the add-email flow, implying it should be used after receiving an OTP during that flow. It also provides explicit access prerequisites: a Proof account and either PROOF_API_KEY configuration or signing in via start_login. It does not explicitly name alternatives or exclusions, but the context is clear.

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