List all mailboxes accessible to your authenticated account. This shows the available folders and email accounts for further mail operations.
Lists mailboxes accessible to the authenticated account.
| Name | Required | Description | Default |
|---|---|---|---|
| apiKey | 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?
With no annotations provided, the description carries the full burden, but it only states the action and scope. It implies a read-only list operation and authentication dependency, yet does not disclose response format, pagination, or error handling. This is minimally transparent but not misleading.
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, dense sentence that front-loads the action and adds a useful scope qualifier. There is no filler, redundancy, or wasted wording.
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?
The tool has no output schema and only one optional, undocumented parameter, yet the description does not explain what the response contains or how apiKey influences behavior. An agent would not know whether to supply apiKey or what format the returned list takes, leaving important context missing.
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 input schema has 0% description coverage, and the tool description never mentions apiKey. The parameter name and pattern '^amk_.*' suggest an API key, but its purpose, whether it is required, and how it affects the call are entirely undocumented.
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 ('Lists') and resource ('mailboxes'), and adds a scope qualifier ('accessible to the authenticated account') that clarifies the operation. This clearly distinguishes it from sibling tools like assistantmail_list_messages and assistantmail_get_mailbox, even without naming them.
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 is given on when to use this tool versus alternatives. There is no mention of filtering, pagination, or any conditions under which a different mailbox-related sibling tool would be more appropriate, leaving the agent to infer from the name alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.