Forward a message

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

The description adds context about saving a draft unless mode='send' and explains forward_as options, which goes beyond annotations. However, it does not clarify the destructiveHint=true (e.g., what is destroyed) or mention auth or rate limits.

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 brief (three sentences) and front-loaded with the primary purpose, then details. It is efficient and well-organized, though some parameter explanations could be more concise.

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 tool's complexity (12 parameters, output schema present), the description covers the core function and key options but omits details on return values, destructive behavior, and many parameters. It is adequate 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?

With 0% schema description coverage, the description compensates by explaining 'body', 'forward_as', and 'mode' parameters. But most parameters (cc, bcc, confirm, etc.) are left unexplained, limiting its value for correct invocation.

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 identifies the tool as forwarding a message and explains the draft vs send behavior. However, it does not explicitly differentiate from siblings like mail_reply, though the tool name and action are distinct enough.

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 lacks explicit guidance on when to use this tool versus alternatives (e.g., mail_reply, mail_send). It states what the tool does but not the conditions or prerequisites for using it.

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