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

The annotation only says readOnlyHint=false, so the description carries the burden of explaining side effects. It discloses that a verification email is sent, the account is only pending until the link is clicked, no API token is returned, and the token appears once on the verify page. This is substantial behavioral context beyond the annotation.

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 longer than one line but every sentence earns its place: scope, non-return of token, verification flow, configuration, and routing to whoami. It is front-loaded with 'Start onboarding' and proceeds logically through the sequence. No filler.

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 mutating onboarding tool with no output schema, the description covers the full lifecycle from email submission through token configuration and alternative routing. The main missing piece is any explanation of what the API call actually returns beyond not returning a token, and the role of display_name. Overall it gives enough to call correctly.

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 0%, so the description must compensate; it only addresses email by saying 'require an email.' The optional display_name parameter is never explained, leaving the agent to guess its role. This is a clear gap.

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: start onboarding by creating a pending account with an email and sending a verification link. It clearly distinguishes itself from whoami and account_status by describing the pending/verify flow. The verb and resource are unambiguous.

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?

Explicitly instructs 'If you already have a token, call whoami instead,' giving a clear alternative and condition. It also explains the onboarding sequence and the manual verification/token configuration steps, so an agent knows when this tool is the right entry point. This goes beyond generic context.

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