Problems animating a character holding tool?

I'm having some trouble animating a tool. For a quick test, I have done two things: (a) get a free model of a weapon, a stick to hold in player's hand and to be used as a tool, (b) make an animation of a hand movement which will be applied to the tool i have downloaded.

I've tried to link both together by inserting the animation into the tool and adding a new piece of code which is supposed to play the animation on click. Here is its implementation:

local UserInputService = game:GetService("UserInputService")
local Tool = script.Parent

local Anim = script.Parent.Animation -- Animation

local debounce = false

local player = game.Players.LocalPlayer
local thisHumanoid = player.Character.Humanoid 

UserInputService.InputBegan:Connect(function(InputObject)
    if InputObject.UserInputType == Enum.UserInputType.MouseButton1 then

        debounce = true
        local AnimTrack = thisHumanoid:LoadAnimation(Anim)
        AnimTrack:Play()
	print('playing anim') --simple message for debugging purposes
        wait(1) -- Seconds Before You Can Play Animation Again.
        debounce = false

    end
end)

With the above code, when I used an animation which was working only on the left hand (i.e. no weapon), it worked. With an animation on the right hand (i.e. hand holding weapon), no animation plays out. What is wrong in my approach?