The complex challenge of farm management has prompted a search for ways in which scientific knowledge can be acquired and combined with practical know-how and experience to enhance the adaptability, profitability and environmental soundness of agricultural systems. Cognitive tools offer a kind of model-based learning support that acilitates and stimulates critical thinking about the functioning of agricultural production processes and the ways to control them in various and changing situations. The purpose of this paper is to delineate, illustrate and analyse the concept of cognitive tool together with the learning process and conditions in which such a tool would be used. Wereview three such tools built to help understand, improve, adapt or design grazing management practices in pasture-based livestock farms. For each of them we examine the knowledge content of the tool, the way it is represented, the kind of use and the nature of the support it provides to its users.