Harness solves this by putting the status of the agent front and center (or rather on the left vertical tab bar). Each worktree is a tab, the icon shows you if the agent is working (green means working, yellow means waiting on you, red means waiting on a permission prompt). The goal is that all work for a worktree is in one mental space, so you can easily review the agent's work (reviews built in, integrated browsers sorted by worktree, etc)