Introduction: The Real Challenge in AI Agent DeploymentDevelopers working on AI Agent implementations frequently encounter a frustrating paradox: despite using flagship models, refining prompts hundreds of times, and tuning RAG systems repeatedly, task success rates in real-world scenarios stubbornly remain below expectations. The system performs inconsistently—sometimes brilliant, sometimes completely off-track.The fundamental issue lies not with the model itself, but with the operational system surrounding it—the Harness.Understanding Harn...