List sent emails

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

With no annotations, the description carries the burden. It adds behavioral details by specifying ordering ('newest first') and return fields ('delivery status and open/click counts'). However, it doesn't address pagination defaults, rate limits, or the meaning of status values.

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 short sentences with the action front-loaded. Every clause adds information—resource, ordering, output, and use case—leaving no filler.

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?

The description covers the essential return contents and use case, but with no output schema and no annotations, it leaves some gaps around default limit, response format, and failure behavior. Adequate for a simple list but not fully 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?

Only status has a schema description; limit and offset have none, and the description doesn't explain them. The schema coverage is 33%, below the 50% threshold, so the description needed to compensate and didn't.

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 clear action ('List') and target resource ('emails previously sent through Maillog'), and it notes output contents ('delivery status and open/click counts'). This makes it easily distinguishable from its only sibling, send_email, which is a write operation.

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 phrase 'Use this to check whether a message actually went out' provides an explicit use case. It doesn't spell out exclusions or name send_email, but the context of listing vs sending makes the choice clear.

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