list_labels

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

No annotations exist, so the description carries the behavioral disclosure burden. It communicates read-only access via 'List' and states an explicit OAuth scope 'tag:read', which is useful. However, it says nothing about output shape, pagination, ordering, or failure modes for a tool with no output schema.

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 extremely compact: one purpose sentence plus one scope annotation. Every element earns its place, and the core action is front-loaded with no distracting detail.

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—zero parameters, no nested objects, and no output schema—the description provides sufficient context for invocation: what it lists and the required access scope. It does not describe the return representation, but for a simple list_labels operation this is a minor gap.

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 schema description coverage is 100%, so there is no parameter meaning for the description to clarify. The baseline of 4 applies because no parameter information is needed.

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 a specific verb and resource pair: 'List labels.' The added scope 'tag:read' clarifies the read-only nature and distinguishes it from label-creation and other-resource listing tools such as create_label or list_mailboxes.

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?

There is no guidance about when to use this tool versus alternatives such as list_folders, list_mailboxes, or create_label. The resource name implies the use case, but the description does not state conditions, exclusions, or alternatives explicitly.

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