labels-list

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It adds one useful operational detail: case sensitivity. It does not mention read-only status, pagination, authentication, or potential errors, though the output schema likely covers the return shape. The description gives moderate transparency but relies heavily on the tool's simple name.

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 very short and front-loaded: 'List Gmail labels' immediately states the action and object. The extra detail about query syntax and case sensitivity is relevant and non-redundant. The only minor issue is the compact phrasing 'for label: query syntax,' which is slightly awkward but not padded.

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 listing tool with an output schema present, the description provides the essential purpose and a key caveat about case sensitivity. It does not confirm exhaustiveness or Gmail-specific limitations, but nothing critical appears missing for selecting and invoking the tool correctly.

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 input schema fully documents this with 100% coverage. The description does not need to explain inputs, and the baseline for a zero-parameter tool is 4. No additional parameter context is required.

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 identifies a specific verb ('List') and resource ('Gmail labels') and ties them to a concrete use case ('label: query syntax'). This distinguishes it from sibling tools like label-add and label-delete. However, the phrasing 'for label: query syntax' is slightly elliptical and could be misread as filtering by label rather than listing labels intended for use in queries.

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 implies when to use this tool: when an agent needs Gmail label names for constructing label: query syntax. It does not explicitly compare with categories-list or explain when not to use it, leaving some inference to the agent. This is adequate but not fully explicit.

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