Tutorial: Creating an Amazon EventBridge rule for AWS Chatbot
AWS Chatbot only delivers notifications with their original EventBridge event message content to chat channels. If this message content is modified (such as by using EventBridge InputTransformers), AWS Chatbot won't be able to deliver notifications to your chat channels.
You might create an EventBridge rule that unintentionally sends too many notifications to your chat channels. This typically happens with EventBridge rules that trigger on API calls via AWS CloudTrail. To better control the number of notifications you generate, write your EventBridge rules with event pattern based filtering. For more information about EventBridge event patterns, see Content-based filtering in Amazon EventBridge event patterns in the EventBridge User Guide.