list_mailboxes

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

Annotations already convey that the tool is read-only, idempotent, and non-destructive. The description adds no further behavioral context (e.g., performance, error handling, or dependencies). It meets the baseline but does not enhance transparency beyond annotations.

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 (6 words) and to the point. It is well-suited for a simple tool, but could be slightly more informative without losing conciseness, such as mentioning 'returns a list of mailbox objects.'

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 (one required parameter, output schema present), the description is largely sufficient. However, it does not mention that the account parameter is required or that the result is a list, which could be inferred but is not explicit.

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?

Schema description coverage is 100%, and the tool description does not add any meaning beyond what the parameter description already provides. It correctly references the account parameter implicitly but adds no detail about its format or 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 action (list), resource (mailboxes), and scope (for an account). It is specific enough to distinguish from sibling tools like create_mailbox or list_accounts, but could be more explicit about what kind of data is returned (e.g., list of mailbox objects).

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 provides no guidance on when to use this tool versus alternatives. For example, it does not clarify that this tool should be used after listing accounts with list_accounts, or that it only returns top-level mailboxes. No when-not or alternative tool references.

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