When generating CloudFormation changesets, if the changes are "Create" or "Delete", they are fairly obvious and easy to decipher. However, when the changes are "Modify", I can't tell what the modifications are. For example, if I were to add a tag to a resource, CloudFormation generates a changeset that marks the resource for "Modify", but I can't tell that it's adding a tag from just reading the changeset.
In particular, when tagging Lambda functions, the changeset just says, "scope: properties".
Are there tools that can produce a better printout?
There is "JSON changes" which shows the changes and it has details, but its far from perfect. You can read up more here how to interpret the "JSON changes".
I'm not aware of any build in AWS tool to make changset more readable. Maybe there are some third party tools. One thing that people do is to keep CloudFormation templates under git's control. With git you can very easily check and compare different versions of your template.