Commit Intent in AI Harness Engineering
Commit intent is the discipline of having an agent explicitly declare what it is about to do, and why, immediately before it actually invokes a tool — separating the decision from the execution as two distinct steps in the harness.
Concretely, before a tool call goes out, the agent emits a short, structured statement: the action being taken, the target, the expected outcome, and often the reasoning that justifies it. Only after that intent is committed does the harness fire the actual tool call. This sounds redundant — the tool call itself already encodes “what” — but it solves several real problems in agentic systems.
Why it matters
Drift prevention
Without an intent step, models will sometimes reason their way to one conclusion and then call a tool that does something subtly different (wrong argument, wrong target, hallucinated parameter). Forcing the agent to articulate the intent first makes the model commit to a specific action in natural language, then anchors the actual tool call to that statement. Misalignments between intent and execution become detectable.
Gating and approval
The intent is a natural interception point. The harness can pause here for human-in-the-loop approval on irreversible or expensive actions (deletes, payments, prod deploys, sending external messages) without needing to parse and re-validate tool arguments. Action-type taxonomies in skill systems (e.g. “prohibited / explicit-permission / regular”) are essentially built on this idea.
Observability and replay
Intents form an audit log of reasoning that’s far more useful than just “tool X was called with args Y.” When debugging a bad trajectory, you can see where the agent’s thinking went wrong, not just where the call went wrong.
Coherence across multi-step plans
When an agent commits intent for a sequence (“I will: first check the schedule, then update the deployment, then verify the rollout”), it tends to stay on plan instead of getting distracted by intermediate tool outputs.
Relation to other patterns
The pattern overlaps with — but isn’t quite the same as — ReAct’s “Thought” step or tool preambles:
- ReAct mixes reasoning and action loosely; the “Thought” is freeform and not structurally enforced.
- Tool preambles are often descriptive (“I’m going to search for X”) and sometimes emitted alongside or after the call.
- Commit intent is the stricter discipline of making the pre-action declaration a structured, required artifact that the harness can inspect, gate on, and log independently from the tool call itself.
Design implications
When building a harness with commit intent:
- Treat the intent as a first-class artifact in the trace, not just freeform text inside a thinking block.
- Make gating policies key off intent metadata (action category, target, reversibility), not raw tool names.
- Allow the harness to reject an intent and force the agent to re-plan, rather than only being able to fail after a tool call has already happened.
- Log intents and tool calls as paired records so post-hoc analysis can detect intent/execution drift.