list_folders

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

With no annotations, the description conveys a read-only listing behavior and a complete scope ('all'), but it does not disclose return format, pagination, authentication, or other behavioral traits. Acceptable for a simple list tool, but not rich.

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?

A single sentence with no wasted words. It states the action and the exact scope of what is listed.

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 parameterless list operation, the description is largely complete. The only minor gap is that no output schema is provided and the return value shape is not described, though the tool's purpose makes it reasonably inferable.

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 unitary, so there is no parameter burden for the description to carry. The absence of parameter details is appropriate and the schema covers everything.

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?

States a specific verb ('List') and resource ('all Yahoo Mail folders/mailboxes'). This clearly distinguishes the tool from the email-operation siblings such as search_emails, get_email, and delete_email.

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 the tool is used when a folder list is needed, and all siblings operate on individual emails rather than folders. However, it does not explicitly state when to choose this tool over alternatives or mention any exclusions.

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