Complete Agent Harnesses: Why Both Guides and Sensors Matter

Controlling AI agent behavior requires balancing two mechanisms: guides that proactively shape behavior (rules, examples, style guides) and sensors that reactively detect problems (tests, linters, audits). Most teams over-invest in one approach and neglect the other, leading to predictable failures—either overwhelming rule fatigue or prohibitively slow feedback loops. Understanding this distinction is critical for teams deploying agents at scale.