An event-triggering methodology is proposed on an observer-free output feedback cooperative control scheme for linear multiagent systems in order to schedule the exchanged information between the agents depending upon error exceeding user-defined thresholds for reducing wireless network utilization. Specifically, the cooperative control scheme is designed for continuous-time, minimum phase, and high-order linear multiagent systems in the context of a containment problem (i.e., outputs of the follower agents converge to the convex hull spanned by those of the leader agents). The proposed observer-free output feedback cooperative control scheme with event-triggering guarantees follower agents' system stability and performance, and also does not yield to a Zeno behavior. An illustrative numerical example complements the proposed theoretical contribution.