Item description duplicates should not be allowed and shouldnt be editable once transactions are in

Summary:

Hi,

So we are using sequence-based generation for item codes and for item description it is user defined. We noticed that description can be repeated and not unique like item code or UOM. We have two query:

1. Is there any way we can create a restriction where item description cannot be repeated again. (Check image below: It shouldn't allow same description)
2. Once the item is created. Transactions are in, descriptions should not be editable. Please suggest how to achieve this. Can we play around with Custom roles to keep it view only. Or throw a validation error once description is created and transactions are in it shouldn't allow to edit