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 disclosure burden. It contributes one useful fact - 'Read-only' - and the word 'top-level' implies non-recursive listing, but it says nothing about return format, ordering, or whether the list can be empty.

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?

Two short sentences, front-loaded with the scope constraint and the read-only trait. Nothing is padded or redundant.

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?

For a simple single-parameter read tool with no output schema and a fully documented parameter, the description covers purpose and safety adequately. It could add a bit more on what a 'top-level mailbox' means or when to call it, but nothing essential is missing.

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 coverage is 100% and the single account parameter is already well documented (including its source, list_accounts). The description's 'in one Apple Mail account' only restates what the schema provides, so the baseline 3 applies.

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?

States a specific verb (list), resource (mailboxes), and scope qualifier (top-level, in one Apple Mail account). The resource name distinguishes it from message-oriented siblings, but it does not explicitly contrast with any sibling the way a top-tier definition would.

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 phrase 'in one Apple Mail account' implies the account must be known (and the schema points at list_accounts), but there is no explicit when-to-use statement or mention of alternatives. Usage is inferable rather than stated.

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