I'm currently able to successfully create Alternate Keys in my Plugin by passing in string values. However, when I try to generate one for 'opportunityproduct' using 'productdescription', I get an error. Attempting to create one through the UI shows me that 'productdescription' is not an available attribute for usage even though it is a string field.
Is there a way through the Web API to figure out which string, decimal, or integer fields are available to use in an Alternate Key? I don't see anything under entity definitions or their related attributes