list_mailboxes

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

No annotations are provided, so the description carries the full burden. It does not mention auth requirements, rate limits, or side effects. However, as a listing operation, it has minimal behavioral concerns, and it lists the specific fields returned, offering some transparency. The lack of any behavioral notes is acceptable but not exceptional.

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 two sentences: the first details the output, the second provides usage guidance. There is no redundant information, and critical details are front-loaded. Every sentence adds value, making it highly concise.

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 (single parameter, no output schema), the description is reasonably complete. It explains what data is returned and when to use it. It lacks information on pagination or sorting, but for a straightforward list tool, this is acceptable. The description is adequate for an AI agent to understand the tool's purpose and invocation context.

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?

There is only one parameter, project_id, which is described in the schema as 'The project ID'. The description adds no additional meaning beyond the schema, and schema coverage is 100%. Thus, the description provides no extra value for this dimension, earning a baseline score of 3.

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 action 'List a project's mailboxes' and details the specific fields included, distinguishing it from siblings like get_mailbox (single mailbox), create_mailbox, etc. The verb and resource are specific and unambiguous.

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 advises 'Use before choosing or repairing email defaults', providing explicit context for when to use this tool. While it doesn't name alternative tools outright, it implies the tool is for discovery prior to setting defaults, which is sufficient guidance.

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