Vector Store should not be taken into account if empty

Created a thread, added an (for the moment) empty VS to it, ran an assistant, here is the answer:

“It seems there are no matches for “tout va bien” in the uploaded files. If you have a specific question or need information on a particular topic, please let me know so I can assist you better!”

As the VS is empty, there is NO uploaded file.
I think VS should not be taken into account if empty