verify_email_otp

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

Annotations only provide readOnlyHint=false and destructiveHint=false; the description adds meaningfully to that by disclosing the account/auth prerequisite (PROOF_API_KEY or start_login) and the fact that a correct code finalizes the add-email flow. It omits failure behavior (invalid/expired code) or retry limits, so it stops short of full disclosure.

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?

Two short blocks: purpose first, then an ACCESS note. Front-loaded and mostly waste-free, though the ACCESS paragraph is slightly long relative to the core two-sentence purpose.

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 2-param, no-output-schema tool with annotations covering the safety profile, the description covers purpose, flow position, and auth prerequisites. The main gap is what happens on an incorrect or expired code, which an agent would want to know before retrying.

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 coverage is 100%, with both session_id and code already documented in the schema. The description adds no syntax, format, or sourcing detail beyond what the schema provides, so the baseline 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?

States a specific verb+resource ('Submit the OTP code to verify an email addition') and ties it to a named flow ('Completes the add-email flow'). It is distinguishable from cousins like resend_email_otp and start_add_email, though it does not explicitly disambiguate from other OTP-consuming siblings such as submit_verification_code or confirm_domain_email_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?

Usage is implied by the flow language ('Completes the add-email flow if the code is correct') and by the ACCESS note explaining the sign-in prerequisite. However, it never explicitly names the alternative (e.g., resend_email_otp when the code never arrives) or states when NOT to use this versus the other code-consuming tools.

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