How to find and set tool in script? (read desc)

Tool's name is "Excalibur", parent "Workspace". But how to put that in script? I tried local Tool = script.Parent.Workspace and local Tool = Excalibur and many other things, but nothing worked. (my scripting skills are almost zero)

-- R attack
local Tool =         -- here
local Player = game.Players.LocalPlayer
local Character = Player.Character or script.Parent
local Humanoid = Character.Humanoid
local UserInputService = game:GetService("UserInputService")
local AnimationID = 'rbxassetid://4868889544'
local Animation = Instance.new("Animation")
Animation.AnimationId = AnimationID
local LoadAnimation = Humanoid:LoadAnimation(Animation)
local key = 'R'
local debounce = true

Tool.Equipped:Connect(function() 
    UserInputService.InputBegan:Connect(function(Input, IsTyping) 
        if  IsTyping then return end
        if Input.KeyCode == Enum.KeyCode[key] and debounce == true then
            debounce = false
            LoadAnimation:Play()
            wait(5)
            debounce = true
        end
    end)
end)

Tool.Unequipped:Connect(function() 
    LoadAnimation:Stop()
end)

To find an instance that is the child of another instance, use :FindFirstChild()

local tool = game.Workspace:FindFirstChild("Excalibur")

This will return the first child of Workspace with the given name, or nil if none such instance exists.

For more info, see the relevant documentation.