You can have code assist insert argument names automatically on method completion. This behavior can be customized on the Java > Editor > Code Assist preference page (see the Fill argument names on method completion checkbox.) For example, when you select the second entry here,
code assist will automatically insert argument names:
you can then use the Tab key to navigate between the inserted names.
Code assist can also guess argument names - based on their declared types. This can be configured by the Guess filled argument names checkbox on the Java > Editor > Code Assist preference page.