How to add Idle Aniimations to tools?

Based on this video: https://www.youtube.com/watch?v=dRGEAethTGA The owner of it said that idle animation WILL NOT work, I am asking for someone to modify the script from the owner that can have the capability to do idle animations thanks

Something like this could work in a script inside the tool:

local tool = script.Parent
local anim = Instance.new("Animation")
anim.AnimationId = "http://www.roblox.com/Asset?ID=144884906" --replace with id
local track
tool.Equipped:Connect(function()
	track = script.Parent.Parent.Humanoid:LoadAnimation(anim)
	track.Priority = Enum.AnimationPriority.Action
	track.Looped = true
	track:Play()
end)
tool.Unequipped:Connect(function()
	if track then
		track:Stop()
	end
end)