Creates a dedicated email address for an AI agent and returns the mailbox details, so the agent can use its own address for email tasks.
Create an email address for an AI agent. Returns the mailbox with its address.
| Name | Required | Description | Default |
|---|---|---|---|
| domain_id | No | Domain UUID for a custom-domain address | |
| local_part | No | Local part of the address, e.g. support. Random if omitted. | |
| display_name | No | Human-readable label |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden, but it does disclose one behavioral fact beyond structured data: it returns the created mailbox including its address (valuable since there is no output schema). It says nothing about auth/permission requirements, duplicate-address behavior, or whether creation is idempotent — significant gaps for a mutation tool with zero annotation coverage.
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 sentences, zero waste, and the core action is front-loaded. The second sentence earns its place because it compensates for the absent output schema.
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 three-parameter, all-optional create tool with no annotations and no output schema, the description covers purpose and return shape but omits failure modes (duplicate address, invalid domain, permissions). Adequate minimum, not complete.
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 all three parameters are already documented in-schema (including the 'random if omitted' default for local_part). The description adds no meaning beyond that, so the baseline of 3 applies.
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?
Specific verb+resource: 'Create an email address for an AI agent' tells an agent exactly what is produced and for whom, which distinguishes it from domain tools like add_domain or template tools. However, it never references sibling mailbox tools (list_mailboxes, delete_...) to sharpen the boundary.
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 when-to-use, when-not-to-use, or prerequisite guidance is given. The agent must infer from the schema alone that domain_id is only relevant for custom-domain addresses, and nothing explains what happens if a mailbox already exists.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.