Agent coordination based on Activity Theory postulates that agents control their own behavior from the outside by using and creating artifacts through which they interact. Based on this conception, we envisage social engagements as first-class resources that agents exploit in their deliberative cycle (as well as beliefs, goals, intentions), and propose to realize them as artifacts that agents create and manipulate along the interaction, and that drive the interaction itself. Consequently, agents will base their reasoning on their social engagement, instead of relying on event occurrence alone. Placing social engagement at the center of coordination promotes agent decoupling and also the decoupling of the agent specifications from the specification of their coordination. The paper also discusses JaCaMo+, a framework that implements this proposal.