combell_mailboxes_list

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the description need not repeat safety. It adds the output detail of including maximum and used size, but does not disclose any further behavioral traits such as pagination, ordering, or error conditions. With annotations covering the safety profile, a 3 is appropriate.

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?

A single, well-formed sentence that front-loads the main action and result. No unnecessary words or repetition. Ideal length for the purpose.

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 list tool with one parameter and no output schema, the description covers the core purpose and the key output (max and used size in MB). It does not specify the exact structure of the returned list (e.g., mailbox identifiers, aliases), but given the simplicity and annotation coverage, it is reasonably complete.

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 parameter description is already clear ('The domain name whose mailboxes to list'). The tool description adds no extra semantic detail beyond what the schema provides, so the baseline 3 is correct.

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 uses a specific verb ('List') and resource ('mailboxes of a domain') and adds the distinguishing detail that it returns maximum and used size in MB. This clearly separates it from sibling tools like combell_mailboxes_get, which targets a single mailbox.

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 usage when a domain's mailboxes need to be listed, but it does not explicitly mention when to prefer this tool over alternatives like combell_mailboxes_get. The context of siblings provides the contrast, but the description itself offers no direct guidance.

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