I want this because if I put my tool away while using it, it results in an error, a way to stop it erroring would also be an acceptable answer.
I don't know of any other way other than a loop. So lets do this:
while true do wait() if game.Players.LocalPlayer.Backpack:FindFirstChild("RocketLauncher") then game.Players.LocalPlayer.Backpack.RocketLauncher.Parent = game.Players.LocalPlayer.Character end end
Replace "RocketLauncher" with your tool name. When a tool enters the players character, the character equips it.
You may still receive an error because the player is able to de-equip the tool, however this is less than a second.
While making this loop in studio, I was only able to get it to work when using "FindFirstChild" Other more conventional methods exists.