List 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 adds useful context by stating that folder listing includes message and unseen counts, which is beyond what a bare 'list folders' would imply. However, it does not disclose output structure, hierarchy, or any potential side effects, though 'list' inherently suggests a read-only operation.

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 with no filler. It front-loads the verb and resource and includes the key detail about counts. Every word earns its place for a tool of this simplicity.

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?

Given that there is no output schema and no annotations, the description is the sole source of information. It tells the agent it will receive counts, which is helpful, but it does not explain the return format or scope (e.g., all folders vs. subscribed). For a zero-parameter tool this is adequate but leaves some uncertainty about what the response will look like.

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 tool has zero parameters, and the schema is empty. Per calibration, a zero-parameter tool receives a baseline of 4 since there is nothing to explain. The description does not need to compensate for any missing parameter documentation.

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 uses a specific verb ('List') and resource ('IMAP folders') and adds the distinguishing detail 'with message / unseen counts'. This clearly separates it from sibling tools like list_emails, so an agent can select it without ambiguity.

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 clearly implies the tool is for folders, not emails, by saying 'IMAP folders'. While it does not explicitly name alternatives or exclusions, the context is sufficiently clear for an agent to know when to use it, especially given sibling names like list_emails and search_emails.

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