Abstract: Recent advances in artificial intelligence capabilities have rapidly shifted the narrative around AI agents from theoretical to practical. This article examines the emerging landscape of functional AI agents that can autonomously perform meaningful knowledge work tasks. Drawing on recent research and organizational examples, it analyzes how these agents are transforming workflows across industries, the implications for organizational performance, and potential impacts on knowledge workers. The evidence suggests that while narrow-purpose agents already demonstrate effectiveness in domains like research, coding, and content creation, general-purpose agents are now emerging with capabilities to handle diverse tasks with minimal supervision. Organizations adopting strategic approaches to AI agent integration—focusing on augmentation rather than replacement, establishing appropriate governance, and reimagining work processes—are positioned to realize significant productivity gains while fostering valuable human-AI collaborations. The paper concludes with a framework for building sustainable AI agent capabilities within organizations.