Technology development often has profound consequences for human agency. Considering the evolution of seemingly mundane tools, such as pens, can help us anticipate the consequences of emerging technology. We consider how the evolution of pens might guide automation and artificial intelligence (AI) design. Automation and AI change activities by trading degrees of freedom—expanding, eliminating, or resolving—to transform intent into action. The evolution of pens shows three approaches to trading degrees of freedom. A technology-based approach eliminates degrees of freedom to improve efficiency A human-centered approach trades degrees of freedom to enhance human agency. A system-centered approach trades degrees of freedom to address domain entropy and promote resilience. We link trading degrees of freedom to concrete design considerations with examples from pens, large language models, and vehicle automation. We hope that analyzing a technology far removed from AI and vehicle automation will provoke new discussions of humanautomation interaction.