Action items are a common way to track agreements between stakeholders. I see them tracked in excel spreadsheets. Treat an action item as an agreement between the actionee and receiver for a piece of work. An action item usually includes a actionee, a receiver, status, a due data and a short description of the work agreed to. The metric to watch is the number of open and closed items over time.
But an action item list is only a map. It is not the territory. To understand how well coordinated a team is I would consider how confident I feel that the different people understand each other's position and what is expected of them. In part, I would look at how well everyone is communicating. The trick is to determine this. One way to get there is to be engaged with all the people on the team, individually and in groups.
Signs of a lack of coordination among the team include people talking over one another, people repeating their position without listening to someone else, the need to repeat matters in coordination meetings, the need for too many coordination meetings...