list_folders

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

With no annotations, the description carries the burden of behavioral disclosure. It states the tool lists 'all available' folders, but does not clarify whether the result is a flat list or hierarchical, includes system folders, or what the return format is. This is a minimal but adequate disclosure for a simple 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, front-loaded sentence that directly states the tool's purpose without any wasted words.

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, simple list operation, the description is almost complete. It clearly states what is listed, but does not describe the return value structure (e.g., whether it's an array of strings or objects), which would be expected given the absence of an output schema. Still, it is sufficient for practical use.

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 has no properties (100% coverage by default). The description does not need to explain parameters, so a baseline of 4 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 clearly states the tool's function: 'List all available IMAP folders/mailboxes in your Yahoo Mail account.' It specifies the verb (list), resource (IMAP folders/mailboxes), and scope (Yahoo Mail account), distinguishing it from sibling tools that operate on 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?

While there is no explicit 'when to use' or alternative mention, the context is clear: this tool is for listing folders, whereas all siblings handle email operations. The purpose itself makes the usage obvious, and no exclusions are needed.

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