How can i not unequip a tool but you can only switch tools?

How can i not unequip a tool but you can only switch tools? I can't really wrap my head around it. I didn't do the code when you switch tools. I only tested it for one tool but when i unequip the tool it lags then freezes. This is the error: ? Something unexpectedly tried to set the parent of FastCastGun to ProGamer(Character) while trying to set the parent of FastCastGun. Current parent is Backpack. (x2). This error keep repeating simultaneously with the lag. How can I fix it and how to make the script when you can only switch tools? This applies in many fps games.

Heres my code:

local animateequip = script.Parent.animationequip
local anim = script.Parent.Animation
local equipped = false
animateequip.OnServerEvent:Connect(function(player)
	equipped = true
	if equipped == true then
	local hum = player.Character.Humanoid
	local equip = hum:LoadAnimation(anim)
		equip:Play() -- is it the animation?
		end
	end)
local function characteradded(character)
	local hum = character.Humanoid
	print(character)
	hum:EquipTool(script.Parent)
	script.Parent.Unequipped:Connect(function()-- this one maybe
		equipped = false
		if equipped == false then
			equipped = true
			hum:EquipTool(script.Parent)
		end
	end)
end


local function playeradded(player)
	player.CharacterAdded:Connect(characteradded)
	local charact = player.Character
	if charact then
		characteradded(charact)
	end
end

game.Players.PlayerAdded:Connect(playeradded)

for i,v in pairs(game.Players:GetPlayers()) do
	playeradded(v)
end