Should I do this to stop direct orders?

[sunnykingkoh]

Hello,
I receive many orders which people place without reading anything and we have to end up on cancellation which reduces my orders completion rate.

I am thinking to put a main picture of my gig by writing “Please don’t place direct order”. So my question is, is this OK to do within the rules? I also have seen that a top-rated seller of my field has putten a main gig picture by writing that " Don’t place direct order otherwise order will be canceled".

Looking forward to your reply.
Thank you!