Amazon CloudWatch Events
User Guide

Amazon CloudWatch Events Managed Rules

Other AWS services can create and manage CloudWatch Events rules in your AWS account that are needed for certain functions in those services. These are called managed rules.

When a service creates a managed rule, it may also create an IAM policy that grants permissions to that service to create the rule. IAM policies created this way are scoped narrowly with resource-level permissions, to allow the creation of only the necessary rules.

You can delete managed rules by using the Force delete option. Do so only if you are sure that the other service no longer needs the rule. Otherwise, deleting a managed rule causes the features that rely on it to stop working.