Creates a mail folder, optionally nested under a parent folder, to organize messages before moving mail into it.
Create a mail folder. parent_folder (id or display name) nests it; omit for a top-level folder. Useful before moving mail into a new folder.
| Name | Required | Description | Default |
|---|---|---|---|
| display_name | Yes | ||
| parent_folder | No |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. It does not say what happens on a duplicate display_name, whether creation is idempotent, what permissions are required, or what the call returns (a folder id would plausibly be needed for later moves). For a mutation tool with zero annotation coverage this is a substantial 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?
Two sentences with the core action and the key parameter behavior front-loaded, followed by a short usage hint. Nothing is padded, though the trailing usage sentence is thinner than it could be.
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?
With no annotations, no output schema, and 0% schema description coverage, the definition should explain return value and duplicate-name behavior. It covers the parameters' meaning adequately but leaves the agent guessing about failure modes and what it gets back.
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 0%, so the description must compensate, and it does half the job: parent_folder is explained as accepting an id or display name and being omittable for a top-level folder, which the schema does not convey. display_name is only implicitly characterized as the folder's name; no constraints (uniqueness, length, allowed characters) are given.
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 and resource ('Create a mail folder'), which no sibling shares — list_folders reads, create_folder writes. It also distinguishes the nested vs top-level case. It stops short of noting what the call returns or how it differs from other creation tools like create_draft, but the resource is unambiguous.
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 phrase 'Useful before moving mail into a new folder' implies the workflow (create_folder then move_message) but never names move_message or states when not to use it. Usage context is implied rather than spelled out, so an agent must infer the sequencing.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.