For the Eclipse based Kaleo designer, the user story is where a developer may want to modify an existing workflow-definition that is stored in the Portal database but is not available in the original XML file form. IN Eclipse for the Liferay Server in the SErvers view we could offer a "workflow definitions" node that would when expanded would query the available workflow definitions in the runnting portal and return their names. Then the developer could be given some UI actions on this definition, like view, or edit, or copy into project, etc.
Also if a developer is creating a new workflow definition file it would be nice if the tooling could automatically publish that definition file into the portal without having to go through the control panel > Add workflow definition, etc... Especially since they will likely be making several changes in a row.
So if an API could be exposed that would allow simple CRUD operations on the workflow definitions, would be sufficient for the tooling to be created.