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 behavioral disclosure. It discloses that both inbound and outbound messages are included, but doesn't state whether messages are returned in chronological order, whether the operation supports pagination, performance limits, or what happens with invalid mailbox IDs. The date filtering parameter 'since' implies behavior not described.

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 front-loads the core purpose. It wastes no words, though it could add value with a second sentence about available filters without significant bloat.

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 4 parameters, 0% schema description coverage, no annotations, no output schema, and 21 sibling tools, this description is under-specified. It doesn't explain how results are ordered, whether the 'since' filter is applied to send or receive times, or how this relates to assistantmail_list_messages_reference. An agent cannot confidently build correct invocations from this alone.

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 description coverage is 0%, so the description must compensate for the schema's lack of commentary. The description only describes mailbox scope and does not explain the semantics of 'limit', 'since', or 'apiKey'. The schema provides patterns but not meaning, so the description leaves substantial gaps.

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 states a specific verb ('Lists') and resource ('inbound and outbound messages for a mailbox'), which clearly identifies the operation. However, it doesn't explicitly distinguish itself from sibling tools like assistantmail_list_messages_reference or assistantmail_get_message, so it gets a 4 rather than a 5.

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 gives no guidance about when to use this tool versus alternatives. It doesn't mention filtering options, pagination, or how it differs from the _reference variants. An agent would have to infer from names and schemas alone.

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