validateNewUser

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

With no annotations provided, the description carries the full burden of disclosing behavior. It clearly states the side effect of fully creating the account, the optional password behavior, and the return value of the new API key. This is strong transparency for a mutation tool, though it does not mention whether the OTP is consumed or whether the operation is idempotent.

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 extremely concise: two sentences front-load the core action and then state the optional behavior and return value. Every sentence earns its place, and there is no redundant or filler content.

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?

Given the tool's moderate complexity, no output schema, and no annotations, the description explains the full flow: validate the email-based credentials, create the account, optionally set a password, and receive the API key. It is sufficiently complete for an agent to invoke correctly, though it could mention prerequisites like whether an OTP request must have occurred first.

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 documents all three parameters with descriptions at 100% coverage, so the baseline is 3. The description adds context by tying otp and ref to the emailed code and explaining that password is optional for login, but it does not significantly extend beyond the schema's own parameter descriptions.

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 action—validate the emailed OTP and code reference, then fully create the account—and clearly differentiates this from the sibling validateOtp by emphasizing account creation. It also specifies the optional password feature and the returned API key, leaving no ambiguity about the tool's purpose.

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 conveys the intended usage context: this is the final step after a user receives an emailed OTP, and it completes account creation. It does not explicitly list alternatives like validateOtp for OTP-only checks or requestOtp for sending the code, but the workflow implication is clear enough for an agent to select it appropriately.

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