List Gmail Labels

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint, covering the safety profile. The description adds minimal behavioral context (e.g., 'all labels' and 'user's Gmail account') but does not discuss auth requirements, rate limits, or response format. This is acceptable but not additive.

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 of eight words, efficiently stating the tool's purpose without redundancy. Every word earns its place.

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 list operation with full annotation coverage and an output schema present, the description is complete. It clearly defines the scope ('all labels in the user's Gmail account') and does not need to explain return values or error handling.

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 fully describes the single parameter `user_google_email` with the description 'The user's Google email address. Required.' Since schema coverage is 100%, the description adds no further parameter meaning. Baseline of 3 applies.

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 the specific verb 'Lists' with the resource 'all labels in the user's Gmail account', clearly distinguishing it from sibling tools like manage_gmail_label (which manages labels) and list_gmail_filters (which lists filters). The scope is unambiguous.

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 provides no guidance on when to use this tool vs alternatives. It does not mention manage_gmail_label for label mutations or any other sibling tools, so the agent receives no explicit context on selectable conditions or exclusions.

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