Create mailbox

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

Annotations already establish the safety profile: readOnlyHint=false and destructiveHint=false, so the agent knows this is a non-destructive mutation. The description adds the useful fact that the domain is sourced from the order while the local part is supplied, but it does not disclose failure behavior (e.g., duplicate local_part), idempotency, or response contents. Adds modest context above the annotations but not rich behavioral detail.

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?

Two compact sentences with zero filler: the first names the action and scope, the second explains the address derivation rule. The most important verb-resource information is front-loaded and every clause earns its place.

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 simple 3-parameter operation with 100% schema coverage and no nested objects, the description is adequate for invoking the tool. The main gap is that there is no output schema and the description gives no indication of the response shape or success/failure signals, and duplicate-handling behavior is unmentioned; these are moderate gaps but do not make the tool uncallable.

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% and each parameter already carries a detailed description, including the password complexity rule and the local_part format constraints. The description only restates the domain-from-order relationship already present in the local_part schema description, so it adds essentially nothing beyond the schema baseline of 3.

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-resource pair ('Create a mailbox') and grounds it in the mail-order context, with the second sentence clarifying that the full address is composed from the local part plus the order's domain. It does not explicitly differentiate itself from sibling creation tools like mail_createAliasV1 or mail_createForwarderV1, but the mailbox concept is delineated clearly enough to be recognizable.

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?

No guidance on when to use this tool versus alternatives. The description is purely mechanical and never mentions that aliases, forwarders, or catch-alls exist as lighter-weight alternatives for address routing without full mailbox storage, so an agent choosing among the many mail_* creation siblings gets no decision support.

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