Just wondering, for certain games. Mainly Horror games. You know? Is there a way?
You would use the Equipped event to know that the tool is equipped and the SetCoreGuiEnabled method to get rid of the backpack GUI. Also, please make sure the script inside the tool is a localscript. As well as to remember that tools always need handles to work.
local tool = script.Parent; tool.Equipped:connect(function() game.StarterGui:SetCoreGuiEnabled("Backpack", false); end)