I may not have caught the gist,
but maybe you can try a calculated field of:
IF [Transcript Search (comma delimit)]="" THEN ""
ELSE "Your search for '"+[Transcript Search (comma delimit)]+"' parameters returned:"
which doesn't put anything in the tooltip if no query terms are entered,
but otherwise should put in the query search.
Please see workbook attached in Forum thread.
267654param.twbx 17.1 MB