list_folders

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

There are no annotations, so the description carries the full burden of explaining behavior. It does make the read-only nature clear and specifies that total and unread counts are included. However, it does not disclose whether hidden or system folders are included, whether the list is ordered, or what identifying information is returned for each folder.

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 front-loaded sentence that states the scope, the resource, and the key return data. Every word contributes information, and there is no redundant or filler content.

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 zero-parameter tool, the description is mostly complete: it names the resource scope and the returned counts. Since there is no output schema, it could more explicitly state that folder identifiers/names are returned, which would better support subsequent calls to sibling folder tools, but the description is still sufficient for the tool's simple purpose.

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 has zero parameters and 100% coverage, so there are no parameter details for the description to add. With no params, the description appropriately focuses on what the call returns rather than repeating schema information.

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 action ('List') and a specific resource ('all mailboxes/folders in the one.com mail account'), and it adds return-value context ('total and unread message counts'). This clearly distinguishes it from sibling folder mutations like create_folder, rename_folder, and delete_folder, and from email-list operations like search_emails or get_recent_emails.

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 gives no explicit guidance on when to use this tool versus alternatives. It is implicitly useful for discovering available folders before calling folder mutations, but it never says this, nor does it contrast with sibling tools such as search_emails or get_recent_emails. The usage context must be inferred rather than stated.

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