"Improved team communication" is broadly advocated in the discourse on safety but rarely supported by a precise understanding of the relationship between specific communication practices and concrete improvements in collaborative work processes. We sought to improve such understanding by analyzing the discourse arising from structured preoperative team briefings among surgeons, nurses, and anesthesiologists prior to general surgery procedures. Analysis of observers' fieldnotes from 302 briefings yielded a two-part model of communicative "utility", defined as the visible impact of communication on team awareness and behavior. "Informational utility" occurred when team awareness or knowledge was improved by provision of new information, explicit confirmation, reminders, or education. "Functional utility" represented direct communication - work connections: many briefings identified problems, prompting decision-making and follow-up actions. The crux of the model is an elaboration of the causal pathway between a specific communication practice (the team briefing), intermediary processes such as enhanced knowledge and purposeful action, and the quality and safety of collaborative care processes. Modeling this pathway is a critical step in promoting change, as it renders visible both the latent dangers present in current team communication systems and the specific ways in which altered communication patterns can impact team awareness and behaviors.