So basically i just want to know how i would make a tool with a custom walking animation only for that one tool.

Ok so heres an edit i managed to figure it out somehow but whenever i Unequip the tool the animation doesen't stop.

tool = script.Parent
tool.Equipped:connect(function()
local UIS = game:GetService('UserInputService')
local Player = game.Players.LocalPlayer
local Character = Player.Character

UIS.InputBegan:connect(function(input)--When a player has pressed LeftShift it will play the animation and it will set the normal walking speed (16) to 35.
 if input.KeyCode == Enum.KeyCode.D then
  local Anim = Instance.new('Animation')
  Anim.AnimationId = 'rbxassetid://1297032259'
  PlayAnim = Character.Humanoid:LoadAnimation(Anim)
  PlayAnim:Play()
 end
end)

UIS.InputEnded:connect(function(input)
 if input.KeyCode == Enum.KeyCode.D then
  PlayAnim:Stop()

tool.Unequipped:connect(function()
	PlayAnim:Stop()
end)

 end
end)    
end)