List Child Mail Folders

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only mentions a permission requirement ('Requires delegated Mail.Read'), which is useful, but it does not disclose other behavioral traits such as whether hidden folders are included by default, if it returns only immediate children, or if it has pagination limits. The tool's read-only nature is implied but not explicitly stated.

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 very concise, with the core purpose stated in a single sentence. The inclusion of Chinese intents adds a slight redundancy but may serve a purpose for international users. Overall, it is well-structured and front-loaded, earning a high score despite the minor extra line.

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?

This is a simple list operation, and the description covers the essential function and a key prerequisite (Mail.Read permission). However, it does not mention the return format or any default behaviors (e.g., hidden folders, max results). Given the absence of an output schema and annotations, a bit more detail would make it complete, but it is acceptable for a basic tool.

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 provides 100% description coverage for all three parameters (top, folderId, includeHidden), so the baseline is 3. The description text adds no additional parameter-level information beyond the schema, leaving the agent to rely on the schema alone.

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 function: 'List child folders under a mailbox folder.' It uses a specific verb ('List') and resource ('child folders'), which is immediately understandable. However, it does not explicitly distinguish this from the sibling tool mail_list_folders, though the 'child' qualifier strongly implies the difference.

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 provides no guidance on when to use this tool versus alternatives. It does not mention related tools like mail_list_folders or explain scenarios (e.g., drilling down a folder hierarchy). The usage context is merely implied by the phrase 'under a mailbox folder,' which is not sufficient explicit guidance.

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