list_gmail_labels

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

With no annotations, the description appropriately conveys that this is a read-only operation (listing). However, it does not mention return format, pagination behavior, or authentication requirements. The simplicity of the tool mitigates the need for extensive disclosure, but some detail on output would improve transparency.

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, clear sentence with no extraneous words. It is optimally concise and front-loaded for quick understanding.

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?

Given the tool's simplicity (no parameters, no output schema, no annotations), the description is functional but lacks details about the structure of returned data (e.g., label IDs, names, types). An agent would benefit from knowing what fields are included in the output, especially since no output schema is provided.

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?

Input schema has no parameters, so the description has no burden to explain parameter semantics. Schema coverage is trivially 100%. Baseline for 0 parameters is 4, and the description adds no contradicting 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?

Description clearly states the verb 'List' and resource 'all user labels in Gmail'. It succinctly defines the tool's purpose and naturally distinguishes from siblings like 'create_gmail_label' which creates rather than lists.

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?

No usage guidance is provided. Does not mention when to use this tool versus alternatives, such as before creating a label to check existing ones, nor any conditions or prerequisites.

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