TIP: It is informative to use the 'Show Java' option on the 'Actions' Button on the Activity Screen in the Designer Studio - I used this to remind myself how to get at the API needed to fetch stuff from the parameters page for instance : just create a standard 'Property-Set' step which references 'Param.yourparam' , save the Activity and then 'View Java'.
Also: The Engine Java API is available from the Designer Studio from the Resources > Engine API menu. (on 721, other versions have a 'help' menu).
Useful Engine Classes to look at to start with:
PublicAPI (this is what 'tools' is an instance of, in automatic code)
ClipboardPage (this is what 'myStepPage' is an instance of , in automatic code).