resend_email_otp

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

Annotations already declare readOnlyHint=false / destructiveHint=false, so the safety profile is largely covered. The description adds real value by stating the auth prerequisite and the restart/re-login workaround, but omits key behavioral traits for an OTP resend: whether rate limits apply, and whether a new code invalidates the previous one or its expiry window.

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 action is front-loaded in one short sentence, and the prerequisite note is separated into a distinct ACCESS block. The phrasing 'a session opens this tool — then call this tool again' is slightly circuitous but still compact.

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 single-parameter tool with no output schema, the description covers what the tool does and the auth gate, which is the main thing an agent needs. It stops short of describing the outcome of a successful resend (new code delivery, expiry, invalidation of the old code) or failure modes for an expired session.

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?

Only one parameter (session_id) and schema description coverage is 100%, so the schema already documents it. The description adds no format, sourcing, or validity detail for the session ID beyond implying it comes from the add-email flow. 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 (resend) and resource (OTP code) scoped to 'an in-progress email addition', which differentiates it from siblings like resend_verification or resend_domain_email. It does not name those siblings explicitly, so the distinguishing is by scope rather than routing.

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?

Establishes the context of use (only within an already-started add-email flow) and the prerequisite (a Proof account plus PROOF_API_KEY, or an active session from start_login). It does not say what to do when no session is in progress or how this differs from other resend tools.

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