The operators like |, &, and - are designed to be used in between search terms, which (except for text searches) are always enclosed by { }, which is why Carl's suggestion should work.

The exception to this is AND searches on multiple fields within the same template or with no template specified, where you can use commas to indicate an AND search the different fields:

({[]:[Application Decision]= "Term1", [Application Decision]= "Term2"})

See the Operators section of the help files for more information 

Thanks - the above query resolves the errors and returns the entries.

However, the entries are shortcuts and the revised query finds them only when run from the LF client with 'Resolve Shortcuts' enabled in the client options. From the Workflow Designer, the revised query returns zero entries when using the 'Test Search Query' link.  I've tried checking the box for 'If an entry is a shortcut, use the document or folder that it references' but this didn't change anything. Is there a way to force workflow to return shortcuts?

If I restrict the search from the workflow to only one specific folder  I get shortcuts back when I test the query in the Designer. For example: {LF:LOOKIN="Undergraduate Admissions\Counselors\%(Counselor Number)\Decision Made"} 

But when I search across multiple folders, which is what the revised query is intended to do, I get no shortcuts. (Note:  In this scenario the folders only contain shortcuts, but to prove the query does work I created a document and tagged it with DEFR and it was returned. )