Create a new mailbox for your authenticated Assistant Mail account by providing an address and optional display name.
Creates a mailbox for the authenticated account.
| Name | Required | Description | Default |
|---|---|---|---|
| apiKey | No | ||
| address | No | ||
| displayName | No |
Changes observed during successful MCP inspections.
v1.3.2Input schema / properties / apiKey / formatAdded value: +"starts_with"v1.3.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It discloses that this is a creation operation, but does not mention whether it is idempotent, what happens if the address already exists, whether it requires special permissions, or what the response contains. For a mutation tool with zero annotation coverage, this is a significant gap.
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 a single, short sentence with no wasted words. It is front-loaded with the action and resource, but it is under-specified for a tool with three undocumented parameters.
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?
Given no annotations, no output schema, and 0% parameter coverage, the description is incomplete. An agent would not know what values to provide for address/displayName, what the API key format implies, or what a successful response looks like. The sibling list shows related tools but the description itself does not provide enough context.
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 does not explain the meaning of apiKey, address, or displayName, nor their constraints (e.g., address format, displayName max length). The description adds no parameter-level meaning beyond the schema's raw property names.
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 verb ('Creates') and resource ('a mailbox') for the authenticated account. It is clear enough to distinguish from siblings like list_mailboxes or get_mailbox, though it doesn't explicitly name a sibling alternative.
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, no prerequisites, and no mention of required authentication context beyond 'authenticated account'. The description implies usage but provides no exclusions or conditions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.