Good BI analysts should have a better understanding of the domain. You have to know how to integrate your technical skills and decision-making skills. You should be able to make creative and interpretable visualizations. For this, you need to master Tableau, QlikView, or Power BI visualization tools. BI analyst needs to come up with efficient strategies that help in improving the business.
You can go through this video to know more about what makes a good BI analyst: