Are you writing your own custom workflow step?

If you want to read the values that an author enters into a component dialog, then:@Model(adaptables = Resource.class)will be fine. For more on working with Sling Models on 6.5 - see this article -- Building Experience Manager 6.5 Components using Granite/Coral Resource Types

Post your code that you are using?

In all the years I have worked with AEM, i have not seen this use case.