stalwart_list_mailboxes

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

With no annotations provided, the description carries the full burden. It implies a read-only operation through the verb 'List' and discloses a key behavioral trait: the token's impersonation capability allows access to other user accounts. This goes beyond basic listing semantics, though it doesn't detail output format or error handling (mitigated by the output schema).

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 extremely concise: a one-sentence purpose followed by a single parameter bullet. It is front-loaded with the primary function and contains no redundancy or filler.

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 one-parameter list tool, the description covers purpose, parameter semantics, and access control context. With an output schema present, there is no need to describe return values, and the description is sufficient for an agent to correctly invoke the tool.

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 description thoroughly explains the only parameter, account_id, noting the special value 'b' for postmaster/admin and clarifying that other accounts can be accessed via impersonation. This adds substantial meaning beyond the schema, which only provides a default value and title.

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 mailboxes (folders) of an account' and specifies the output includes 'email counts'. This makes the tool's purpose unambiguous and distinct from sibling tools like stalwart_list_accounts or stalwart_list_identities.

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 implies when to use the tool: whenever mailboxes for an account need to be listed with counts. It provides context about the account_id parameter, including the default admin account and impersonation access, but does not explicitly mention alternative tools or exclusions.

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