gmail.list_messages

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

With no annotations, the description carries the full burden of behavioral disclosure. It does not mention whether the operation is read-only, whether it returns message metadata or full bodies, or any effects like marking messages as read. The description is minimal and lacks any safety or side-effect information.

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 gets to the point quickly. However, it is under-specified, but conciseness itself is fine.

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 has an output schema, so return values are covered, but the description lacks usage context, alternatives, parameter details, and behavioral caveats. Given the sibling tools include read_message and send_message, more guidance is needed to understand when listing is appropriate.

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 schema has zero descriptive coverage for parameters, and the description only hints that 'query' filters results. It does not explain the Gmail search query syntax, the format of the 'account' parameter, or their defaults and constraints.

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 clearly states the tool lists Gmail messages for an account, with optional query filtering. The verb 'list' differentiates it from sibling tools like read_message and send_message, though it does not explicitly distinguish its role. The scope is clear.

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 guidance is provided on when to use this tool versus gmail.read_message or calendar/drive tools. It only mentions optional query filtering, without any context such as 'use this to search messages' or exclusions.

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