HI,

If you do not want to execute 'action a worklist' rule, which is same as not advancing the task, you can always add a condition (The form Form passes validation <configured>) in the form rule. In this validation configuration, check fields that need to be required before submiting. Hope it works for you.

I tried that for SharePoint 2013 Document Library, it didn't work. When the document is uploaded, no matter whether you provide the values of the metadata or not, the workflow will started. I want to make it like , start the workflow only after all the values are added and submitted.

A simple solution might be to start the workflow on add, check that the data was filled in correctly and if not assign a task to the person who uploaded to correct the data. Then they can open the form, correct the data before the main worflow steps start. Alternately you could just end the workflow and start another when the data is changed.

Does this seem to match what you need?