The tool weld is preventing the arm from being animated
Remove RightWeld and replace it with a Motor6D when equipping a tool that is intended to work with animations, it may appear misaligned so manipulate C0 and C1 or open the built-in Roblox animation editor and place the tool within the animation rig, remove the animation rigs’ RightWeld, replace it with a Motor6D and add the tools’ handle to the Animation Editor, then overwrite the existing animation.