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

Annotations only mark it as a non-idempotent, open-world write; the description goes well beyond that with side effects (email sent, nothing created until the user approves), privacy behavior (same answer whether or not the address has an account), a rate limit (3 sign-up emails per address per hour), and secret-handling guidance for claim_token.

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?

Sentences are dense and front-loaded: purpose, constraints, flow, returns, limit, in that order. It runs a bit long and repeats the free-mailbox-provider list that already appears in the email schema, which is the only wasted 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 four-parameter, annotation-covered write tool with no output schema, the description covers side effects, approval flow, error behavior, return fields, and the required follow-up tool. Nothing an agent needs in order to call it correctly is missing.

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%, so the baseline is 3, and the description adds real constraint semantics for email (consent, work-domain requirement, failure code) plus the user-facing role/agent/name framing already spelled out in the schema. It gains a point over baseline but partly repeats the provider list already present in the email parameter description.

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?

Opens with a specific verb+resource: asking WarpSearch for an account and API key on the user's behalf. It also names the sibling tool ('pass it to claim_registration'), so the agent can place it in the two-step registration flow without opening either schema.

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?

Explicit prerequisites (only an email the user gave you, with consent, work domain only) and explicit exclusions (personal/free providers are refused with code personal_email; ask for a work address instead of retrying). It also describes the full approval handoff the user must complete, which tells the agent when this tool is the right step versus claim_registration.

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