How do I make a tool in my backback appear when I want it to?

You can utilize the AnimationTrack.Stopped() event for this case, to make the Tool appear after the animation has finished playing. Here's an example script:

-- Play the animation
AnimationTrack.Stopped:Connect(function()
	Tool.Parent = Player.Backpack
end)
-- The tool has now appeared in the player's backpack

Keep in mind to define the AnimantionTrack, Tool and Player variables in the above script for it to work as expected.