assistantmail_list_messages

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

No annotations are provided, so the description carries the burden of disclosure. It states it lists messages but does not disclose whether results are paginated, whether it includes both read and unread, whether it requires the apiKey parameter in all cases, or what the output format is. Since it's a list operation with no destructive effects, the description is adequate but lacks depth.

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 a single, concise sentence that is front-loaded with the core action. It is appropriately short, but it omits critical parameter details that would make it more useful, so it's not perfect.

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 0% schema coverage, 4 parameters, and no output schema, the description is inadequate for an agent to confidently invoke the tool correctly. The agent lacks guidance on how to specify the time range (since), pagination (limit), or authentication (apiKey), which are essential for correct use. The description is too minimal given the schema's lack of support.

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 schema description coverage is 0%, meaning the schema provides no descriptions for the parameters. The description of the tool does not explain the meaning or purpose of mailboxId, limit, since, or apiKey. For example, 'since' is a date-time filter but not mentioned in the description. This forces the agent to infer parameter semantics from names alone, which is insufficient.

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 tool lists inbound and outbound messages for a mailbox, using a specific verb and resource. It is distinct from sibling tools like get_message (single message) and list_mailboxes (mailboxes, not messages), though it doesn't explicitly differentiate from them.

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 (listing messages for a mailbox) but provides no explicit guidance on when to use this tool versus alternatives like get_message (for retrieving a single message) or list_mailboxes. It does not state conditions to avoid using it or when to prefer other tools.

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