iam_reply

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 reply preserves originator and routing, which is useful. However, it does not mention whether the reply adds to a thread, how attachments are handled, or any idempotency or safety traits. With no annotations, more behavioral context is needed.

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 action, and no redundant words. It is concise, but the brevity sacrifices completeness.

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 7 parameters, 0% schema description coverage, and no annotations, the description is insufficient. It does not explain the purpose of each parameter, nor does it clarify the distinction from iam_send or iam_read. The existence of an output schema does not compensate for missing input parameter guidance.

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 0% and the description adds no information about any of the 7 parameters (message_id, body, cc, to, subject, references, attachments). While parameter names are somewhat self-explanatory, the description fails to clarify required parameters or special formats (e.g., message_id format). This is a significant gap.

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 tool sends a reply in an existing thread, with the verb 'Send' and resource 'existing thread'. The phrase 'preserving originator and routing' adds specific context. It distinguishes from siblings like iam_send (new message) and iam_inbox (list). However, 'substantive reply' is somewhat vague.

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 use when replying in an existing thread, contrasting with iam_send for new messages. However, it does not explicitly state when to use or avoid this tool, nor does it mention alternatives like iam_read for reading. The guidance is implied but not explicit.

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