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

With only readOnlyHint=false in annotations, the description carries the rest: an email with a one-time verify link is sent, a human must click it, the new token is shown once on the verify page, and old tokens are revoked immediately. It also discloses a rate limit ('a few requests per hour per email'), all beyond structured data.

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?

Front-loaded with the action, then the workflow, then the usage condition and exclusion. Five sentences, each adding a distinct fact with no repetition.

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 one-parameter mutation tool with no output schema, the description covers the full lifecycle (request, email, human verification, one-time token display, revocation) plus rate limits, so an agent knows what will happen and what the user must do.

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 0% and the single parameter has no inline description, so the description must compensate — and it does, specifying that the email must be 'the email the account was registered with'. It doesn't cover format edge cases, but the essential meaning is supplied.

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 and resource ('Re-issue the API token for an existing account') and explicitly scopes it to existing accounts. It is immediately distinguishable from create_account, which it names directly.

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?

Gives the triggering conditions ('token was lost, rotated, or is being rejected as "invalid or expired"') and an explicit exclusion with the alternative ('does not create a new account — for a brand-new account use create_account'). No inference required.

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