This project addresses tool use by intelligent agents--so-called cognitive "habile" agents--in their environment. The research is inspired by examples of tool use among animals, ranging from chimpanzees that fish for insects with sticks to crows that bend wire into hooks. Tool use is viewed as a basis for intelligent behavior. The project focuses on three issues: (1) establishing general characteristics of cognitive habile agents, including development of a taxonomy of tools and their usages; (2) identifying core capabilities of habile agents, including their ability to enhance their interaction with the environment via tools, to perform detailed internal simulations of hypothetical scenarios for tool use, and to exploit symmetries in between tools and task constraints to identify opportunities for appropriate action; and (3) evaluating different control architectures (e.g., hierarchical, iterative) for such agents. It builds upon the PI's recent NSF-supported work on agents and graphical user interfaces, which involved issues of control and cognitive modeling. The Broader Impact of this work will be realized in two ways related to undergraduate research and graduate education: undergraduate researchers are being involved in the research through the AURICS (Accelerated Undergraduate Research in Computer Science) program at NCSU, and a new graduate course focusing on building AI systems and topics related to this research (e.g., embodied agents, cognitive modeling, control architectures) is being developed.