If its just a Name and Decision field, I'd suggest making both Name and Decision mandatory fields. You can do this by going to Library Settings > [Your Column] > Toggle the radio button to "Make field mandatory" > Save. This'll make it required to have all the "Mandatory" fields required to be filled out.
If there's a use case for your list where you wouldn't need both Name and Decision then you may want to use validation like the following. I suspect, but don't know for certain, that SharePoint Validation will work without inverting ISBLANK but you could try it as it simplifies things a lot more. I'll put both here just for reference. I'd advise trying the second one first, as if it works, it's easier for someone else to read later on...
=IF( [Name], [Decision], True )
This is the reference I like to use with SharePoint validations: Link to Documentation
Here's the more "official" documentation: office.com Documentation