forward_message

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

No annotations are provided, so the description carries the full burden. It discloses that the original is quoted and its files re-attached, and that the forward begins a fresh thread. This goes beyond the tool name and adds useful behavioral context, though it does not mention permissions or edge cases (e.g., large attachments, failure modes).

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 sentence, front-loaded with the verb 'Forward' and the resource 'a message'. It conveys all key distinctions without waste, making it easy for an agent to quickly understand the tool's purpose.

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?

With 4 parameters fully documented in the schema and no output schema required, the description provides the essential behavioral context (fresh thread, quoting, file re-attachment) that an agent needs to select and invoke the tool. It lacks explicit return-value or permission details, but these are not critical for a simple forward operation.

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 100%, so each parameter (to, text, message_id, from_inbox_id) already has a clear description. The tool description adds no extra parameter-level detail; it only restates that text is an optional note, which is already in the schema. Baseline 3 is appropriate.

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), the resource (a message), and the specifics: new recipients, a fresh thread, quoting the original, and re-attaching files. This strongly distinguishes it from sibling tools like reply_to_message (which continues the existing thread) and send_message (which composes without quoting).

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 when to use this tool: when you want to send an existing message to new recipients as a new thread. It does not explicitly name alternatives or exclusions, but the phrase 'new recipients in a fresh thread' provides clear contextual guidance vs. replying or sending. Sibling tool names reinforce the distinction.

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