Create mailbox

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

With no annotations, the description carries the burden of behavioral disclosure. It does explain that domainAdmin and fullAdmin grant specific administrative powers, and that the domain must pre-exist. However, it does not disclose other behavioral traits such as permission requirements, duplicate address behavior, reversibility, or rate limits, leaving significant gaps for a mutation tool.

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 exactly two sentences, front-loaded with the core action ('Create a mailbox') and immediately followed by essential contextual detail. There is no fluff or repetition, and every sentence 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 create operation with a 100% schema coverage, the description covers the main purpose, the critical prerequisite, and the two optional admin flags. It is missing some behavioral context (e.g., password requirements, response, error handling), but given the schema's richness and no nested objects, it is reasonably complete. A higher score would require disclosure of side effects or return convention.

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 schema already describes all parameters clearly (100% coverage), giving a baseline of 3. The description adds value by explaining the meaning of domainAdmin and fullAdmin in terms of account/domain administration, and by tying the 'address' parameter to the prerequisite that its domain must exist. This goes beyond the schema's simple field labels.

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 opens with 'Create a mailbox', a specific verb and resource that clearly distinguishes it from sibling tools like list/get/update/delete_mailbox. It adds a key scoping detail (domain must exist) that clarifies the tool's exact purpose beyond the name.

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 a clear prerequisite for usage: the domain part of the address must already exist. It also explains the effect of the admin role flags, which helps an agent decide when to set them. However, it does not explicitly mention alternatives (e.g., create_alias) or scenarios when not to use this tool.

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