list_labels

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

No annotations are provided, so the description carries the full disclosure burden. The verb 'List' implies a read-only, non-destructive operation, and the presence of an output schema covers return structure. However, the description does not mention pagination, ordering, or whether all labels are returned, which leaves some behavioral gaps.

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 efficient sentence that front-loads the core action and resource. Every word earns its place, and there is no redundant or filler language.

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 list tool with an output schema, this description supplies what an agent needs: what is listed and that ids are included. The output schema handles return-value details, and no additional behavioral or usage context is essential for correct invocation. The definition is complete relative to the tool's low complexity.

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, so there is no parameter semantics to explain. Per the baseline for zero-parameter tools, this dimension starts at 4. The description does not need to compensate for any schema coverage gaps.

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 Gmail labels.' It also notes that ids are included, which clarifies the useful output. It does not explicitly distinguish itself from sibling list tools such as list_events or list_calendars, so it falls short of a 5.

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 gives no explicit guidance on when to use this tool versus alternatives. Usage is only implied by the name and the word 'List.' Siblings like list_events and list_calendars make the domain boundaries clear enough, but the description does not reinforce them.

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