list_emails

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

There are no annotations, so the description carries the full burden of behavioral transparency. It says 'recent messages' but does not define 'recent', disclose default limits or pagination, describe ordering, or state what fields the response contains. For a list operation this is a notable gap, though the read-only nature is weakly implied by the verb 'List'.

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 two sentences with no filler. The core purpose is front-loaded in the first sentence, and the second sentence efficiently covers the filtering options. Every word earns its place.

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 no annotations, no output schema, and a partially documented parameter set, the description is not complete enough for reliable invocation. It omits return format, default limit behavior, definition of 'recent', and any differentiation from overlapping list tools. These are significant gaps for an agent deciding whether and how to call this 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?

Schema coverage is only 33%, so the description must compensate. It does add value by enumerating valid status values and clarifying that 'recipient' maps to the 'to' parameter. However, the 'limit' parameter is left completely undocumented in both the schema and description, so compensation is incomplete.

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'), the resource ('recent messages'), and the key concept ('delivery status'). The specific status filters (queued, scheduled, sent, delivered, bounced, complained, rejected) make the tool's purpose unambiguous and help distinguish it from siblings like list_threads or list_broadcasts.

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 a use case—finding messages by delivery status or recipient—but provides no explicit guidance on when to prefer this tool over closely related siblings such as list_scheduled_emails, list_webhook_deliveries, or get_email. No alternatives or exclusions are mentioned, leaving routing to inference.

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