Harness, Scaffold, and the AI Agent Terms Worth Getting Right

In the rapidly evolving field of AI agents, terminology often outpaces a shared understanding, leading to confusion among both newcomers and seasoned practitioners. The article explores key terms such as "harness" and "scaffold" in the context of AI agents, emphasizing the importance of distinguishing between them for clarity in discussions. A harness is described as the execution layer that enables the model to act, while scaffolding provides the behavior-defining structure around the model. The glossary aims to offer practical mental models rather than enforce strict definitions, acknowledging the diverse usage of terms across different frameworks. It highlights the significance of context engineering, where designing what an agent perceives at each step can significantly influence its performance. The text underscores that while a model's policy defines its behavior, the agent is a comprehensive system that encompasses both the model and its operational framework, enabling it to interact with its environment effectively.