list_folders

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

With no annotations provided, the description carries the full disclosure burden. 'List' implies a read-only operation, and 'custom folders' scopes the result, but side effects, authorization expectations, and operational limits are not mentioned. The Outlook-style note adds some data-model context but no deeper behavioral guarantees.

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 sentence that is front-loaded with the action and object. The parenthetical adds useful semantic context without redundancy. Every word contributes to understanding the tool's purpose and scope.

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 simple read-only list operation, the description and fully documented parameters are sufficient for an agent to invoke it correctly. It would benefit from a brief note on return value shape or pagination since no output schema is provided, but the current information is adequate for the tool's low complexity.

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 fully documents both parameters, domain and localPart, with examples and 100% coverage. The description only says 'on a mailbox' and adds no additional parameter semantics beyond what the schema already provides, so the baseline of 3 is appropriate.

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, 'List', and a specific resource, 'custom folders on a mailbox', making the tool's purpose immediately clear. It is easily distinguished from sibling tools like list_mailboxes, list_messages, and create_folder.

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 implies usage by specifying that it operates on a mailbox identified by domain and localPart, but it does not provide explicit when-to-use or when-not-to-use guidance. No alternative tools are named, so an agent must infer the right context from the resource type alone.

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