list_folders

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

With no annotations, the description carries the full burden. It discloses the required access scope ('folder:read'), which implies a non-mutating operation, but it does not describe return format, pagination, or whether nested folders are included. This is a modest disclosure above the inherent behavior suggested by 'list'.

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 two concise sentences with no filler. The action and resource are front-loaded, and the scope note adds useful context without repetition.

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 simple one-parameter tool with no output schema, the description covers the core action and parameter. However, it omits output shape, possible pagination, and any behavior around absent or empty mailboxes. It is adequate but not fully complete.

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?

Schema description coverage is 0%, so the description must clarify the parameter. 'List folders of a mailbox' ties mailbox_id to the parent mailbox, but adds no details about id form, source, or accepted values. It provides minimal compensation for the undocumented schema.

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 verb and resource: 'List folders of a mailbox.' This clearly distinguishes the tool from siblings like list_labels or list_mailboxes, and the scope 'folder:read' reinforces the read-only purpose.

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?

Usage is implied: call this tool to enumerate folders for a given mailbox. However, it does not explicitly mention when to prefer this over list_labels or list_mailboxes, nor does it provide exclusions or alternative routing.

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