gmail_labels

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

No annotations are supplied, so the description carries the full behavioral burden. It implies a read-only operation via 'List', but says nothing about whether system labels, nested labels, message counts, or label IDs are returned, nor about result size or pagination for large mailboxes.

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?

One short sentence with no filler and the resource front-loaded. It is efficiently written, though the terseness borders on under-specification rather than maximal conciseness.

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?

The tool is simple (zero params, no nested objects), which lowers the bar, but with no annotations and no output schema the description could reasonably state the shape of what comes back (label names/IDs) and any auth requirement. It is adequate but leaves real gaps.

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 takes zero parameters, so the schema has nothing to document and the baseline is 4. There is no parameter meaning the description could add or omit.

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 ('List') and resource ('the mailbox's folders and labels'), so an agent immediately knows this is a read-only enumeration of label/folder names. It stops short of a 5 because it does not explicitly distinguish itself from siblings like gmail_search, though the resource boundary is clear enough to infer.

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 explicit when-to-use guidance, no mention of prerequisites such as authentication or scopes, and no named alternative. An agent must infer that this is the discovery step used before gmail_search can filter by label; that inference is plausible but not stated anywhere in the description.

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