The Amazon Simple Storage Service (S3) console now reports security warnings, errors, and suggestions from Identity and Access Management (IAM) Access Analyzer as you author your S3 policies. The console automatically runs more than 100 policy checks to validate your policies. These checks save you time, guide you to resolve errors, and help you apply security best practices. By resolving errors and security warnings reported by the S3 console, you can validate that your policies are functional before you attach them to your S3 buckets or access points.
Source:: Amazon AWS