create-mail-child-folder

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

Annotations already convey that this is a write operation (readOnlyHint false, destructiveHint true). The description adds the important nuance that isHidden must be set at creation time if desired, which is behavioral guidance beyond the schema's mere statement of the property. It does not contradict annotations, and the confirm parameter is documented in the schema, so it doesn't need repetition.

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 two concise sentences plus a tip, with the core purpose front-loaded. No redundant content, and the tip is directly actionable. It earns its place without bloat.

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 rich schema (5 params, 2 required, nested body), the description provides the essential context: what it does, how to get the parent ID, and the hidden-folder caveat. It does not describe the return value, but there is no output schema, so that is not required. The confirm parameter is covered in the schema, so the description is sufficient.

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 high (80%), so the baseline is 3. The description's mention of isHidden and the tip about using list tools to find the parent ID largely mirror what is already in the schema for body.isHidden and mailFolderId. It reinforces but does not add new semantic detail beyond the schema.

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 clearly states the tool's purpose: 'create a new child mailFolder' and 'Creates a subfolder inside an existing mail folder.' This distinguishes it from sibling tool create-mail-folder (which likely handles top-level folders) and directly points to the list tools for locating the parent folder. The verb and resource are specific, and the scope 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 description gives a clear tip on how to find the parent folder ID using list-mail-folders or list-mail-child-folders, which is essential for correct invocation. However, it does not explicitly state when not to use this tool (e.g., for top-level folders) nor mention the alternative create-mail-folder. It implies the use case via 'child' and 'subfolder' but lacks explicit exclusion.

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