Steps:

1. Create new Product in English, do not fill Description field.
2. Go to Completeness tab and verify Content section - Description is Not started 
3. Add new Translation, do not fill Description field.
4. Go to Completeness tab and verify Content section - There are two Description field marked as Not started 
5. Edit product in English and fill description.
6. Go to Completeness tab and verify Content section.

Result: There are two Description field marked as Completed.