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

The description discloses critical behaviors beyond the annotations: it is BILLABLE and deducts from account balance, requires authentication, returns an actionId for confirmation, and reveals that the generated password appears exactly once and can never be retrieved again. None of this is present in the annotations, so the description carries and fulfills the full burden.

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 dense but every sentence earns its place: staging, billing, quote prerequisite, actionId handoff, one-time password disclosure, and client settings. Pricing/billing warnings are front-loaded ahead of implementation details.

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 paid two-step action with no output schema, the description is complete: it explains the quote step, the actionId confirmation step, the one-time password behavior, the ability to reset later, and what client settings to share. An agent has the information needed to execute the flow responsibly.

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 100%, so the baseline is 3. The description reinforces the overall flow but adds little parameter-specific detail beyond what the schema already provides; it does not explain term formats, sessionKey mechanics, or localPart constraints beyond the schema.

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 uses a specific verb and resource: 'Stage creation of a paid mailbox on a mail-enabled domain.' It also clarifies that this tool does not immediately create the mailbox, which distinguishes it from namesake expectations and from executeConfirmedAction.

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 gives an explicit workflow: get a quote with getMailboxQuote, confirm the price with the user, call createMailbox, then call executeConfirmedAction with the returned actionId if approved. It also references setMailboxPassword for later changes, giving clear when-to-use and next-step guidance.

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