create_folder

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

With no annotations, the description must carry the full behavioral disclosure burden. It conveys that the tool creates a folder, which is a mutation, but gives no details on permissions, idempotency, duplicate-name handling, or effects on existing folders – significant gaps for a mutation tool.

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?

A single concise sentence with no filler words; information is front-loaded. However, it is so terse that it sacrifices potentially useful operational detail, though that is more a completeness issue than a structure issue.

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 tool with three required parameters, no annotations, and no output schema, the description is too sparse. It does not state what response to expect, error conditions, or whether the mailbox must already exist, so an agent lacks key context for a successful invocation.

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 schema already documents domain and localPart, while name is left undescribed. The description's 'custom folder on a mailbox' implicitly ties name to the folder label but does not explicitly define it or explain how the parameters relate, so it adds limited value 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 a creation action ('Create') with a specific resource ('custom folder') and scope ('on a mailbox'), distinguishing it from sibling folder operations like list_folders and delete_folder. It lacks an explicit definition of what a custom folder is, but the intent 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?

No when-to-use or alternative guidance is provided. The description does not mention prerequisites such as the mailbox already existing, nor does it contrast with create_mailbox, list_folders, or delete_folder, leaving the agent to infer usage solely from the verb.

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