list_mailboxes

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

The description discloses that the tool returns folder names, hierarchy delimiters, and flags, which is sufficient for a read-only listing operation. No annotations are present, so the description carries the full burden, and it does so adequately without contradictions.

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 long, front-loading the core purpose and adding a single practical use case. Every sentence serves a purpose with no redundancy or unnecessary 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 presence of an output schema (so return details are covered elsewhere), the description fully covers the tool's purpose, use case, and return type. With only 3 parameters (1 required), the information is sufficient for an agent to use the tool correctly.

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%, so the parameters are already well-documented in the input schema. The description adds no additional detail about the parameters beyond the schema, 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 verb 'List' and the resource 'mailboxes/folders for an email account', and specifies the returned data (names, hierarchy delimiters, flags). This distinguishes it from sibling tools like 'list_available_accounts' which lists accounts rather than folders.

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 explicitly mentions a use case: 'Useful for discovering folder names before moving emails.' While it doesn't contrast with alternatives, the guidance is clear and practical for an agent.

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