When to use Policy

Hi Everyone,

I’m still new in RASA and confused about policy, i know it will help the agent to perform better, but when and what is the best practice to use policies? I tried some experiment with and without policies, and when i used policies, it’s hard for me to find the perfect hyperparameter and ended with adding more stories to cover the bot, but when i tried without policies, the bot will response everything as long as the user’s query matched the intent as long as the intent in the stories.md. So right now i’m confused, and need guidance about policies too. Thanks