Create Folder

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

Beyond the annotations, the description discloses important behavior: an existing folder name is an error, saved searches are live views with no mail moves, and on IMAP the server may finish later with a null path requiring listFolders verification. It also states the return shape, which is valuable because no output schema is provided.

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 compact and front-loaded, stating the primary creation path first and then the savedSearch alternative and return/error behavior. Every clause carries useful information without unnecessary repetition.

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 non-read-only, non-destructive creation tool with a nested savedSearch object and no output schema, the description covers the key modes, duplicate-name error, return value, and IMAP async caveat. An agent has enough information to invoke it correctly and verify the result.

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 100%, so the schema already documents each parameter in detail. The description still adds meaningful context by identifying parentFolderPath as coming from listFolders and by clarifying that savedSearch creates a live view rather than moving mail.

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 states a specific verb and resource: creating a mail subfolder or saved search. It distinguishes the two modes clearly and references listFolders for the parent path, so an agent can identify the operation without opening the schema.

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?

It explains the two creation modes and clarifies that savedSearch produces a live view with no mail movement, which is useful context for choosing between them. It does not explicitly compare itself to createFilter or state when not to use this tool, but the main usage context is clear.

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