Aristotle’s ethics

Is Aristotle’s ethics sufficiently action guiding? Does it help us make decisions? If I ask what should I do in situation X, Aristotle would seem to say, “Do what the virtuous person would do.” But if I ask how I am to recognize the virtuous person, he would seem to say, “He is one who acts justly.” Is there something circular about this reasoning? Does virtue ethics need supplementation from other ethical systems, or can it solve this problem?