mail_list_messages

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

No annotations provided, so the description must disclose behavioral traits. It fails to mention that the tool is read-only, requires authentication, or what happens on empty results. It only states it returns message IDs, omitting pagination, ordering details, or effect of parameters.

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 sentences with no redundant information. Front-loaded with the verb and resource. Every word serves a 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 tool with 4 parameters, no output schema, and no annotations, the description is severely lacking. It does not explain output format, parameter behavior, or how this tool fits with sibling mail tools. The description is insufficient 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 coverage is 0% (no parameter descriptions in schema). The description only mentions 'mailbox' implicitly via default INBOX, ignoring limit, account, and unread_only entirely. It adds no meaning beyond the parameter names.

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'), resource ('messages from a mailbox'), default mailbox ('INBOX'), and the output ('Mail message ids for follow-up actions'). It differentiates from sibling tools like mail_search_messages by implying a recent listing rather than search. However, 'recent' is ambiguous and could be more precise (e.g., 'ordered by received date descending').

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?

No explicit guidance on when to use this tool versus alternatives like mail_search_messages or mail_get_message. The phrase 'for follow-up actions' hints at a use case (obtaining IDs for subsequent operations) but does not specify context, exclusions, or prerequisites.

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