Do Agent Rules Shape or Distort? Guardrails Beat Guidance in Coding Agents
A large-scale empirical study of 679 GitHub instruction files shows that AI coding agent performance improves by 7-14 percentage points when rules are applied, but surprisingly, random rules work as well as expert-curated ones. The research reveals that negative constraints outperform positive directives, suggesting developers should focus on guardrails rather than prescriptive guidance.