Forward a message

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

No annotations are provided, so the description carries full burden. It discloses that the tool requires user approval before calling, but it does not specify side effects such as whether the message is actually sent or if the original message is marked as forwarded. This is minimally adequate but lacks depth.

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 extremely concise with two short sentences. The first sentence states the core purpose, and the second provides a critical constraint. No unnecessary words are present.

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 lack of annotations, output schema, and limited parameter coverage, the description is incomplete. It does not mention return values, prerequisites (e.g., that the message must be fetched or that uid and mailbox are required), error conditions, or what happens after forwarding (e.g., sends immediately vs. drafts).

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 only 20% schema description coverage (only the 'note' parameter has a description), the description adds no explanation for parameters like mailbox, uid, to, or cc. The description text does not define these fields, making it difficult for an agent to provide correct values.

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 ('Forward an existing message to new recipients'), which is a specific verb+resource combination. It effectively distinguishes itself from sibling tools like reply, send_email, and save_draft by specifying that it forwards an already existing message.

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 includes a critical usage guideline: 'Only call after explicit user approval.' However, it does not provide any context about when to use this tool versus alternatives (e.g., when to forward vs. reply or send as new email), which limits its helpfulness for tool selection.

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