Why does Odysseus not tell his crew the rest of the prediction by the sirens?

Odysseus chooses not to share the full prediction of the Sirens with his crew to prevent them from becoming fearful or demoralized. He knows that revealing the danger they face could lead to panic and hinder their ability to resist the Sirens' alluring song. By keeping this information to himself, he aims to ensure that they remain focused on their task and can successfully navigate past the threat. This decision reflects his leadership and desire to protect his men from despair.