Most developers who tried an AI coding agent in 2023 or 2024 and bounced off it are still thinking about the problem as "prompt engineering" — finding the magic phrasing that gets the model to behave. That framing is outdated. The agents got smarter; the bottleneck moved. Today the difference between an agent that reliably ships correct code and one that hallucinates confidently wrong changes is almost entirely about what's in its context window and when , not how cleverly you phrased the ask...