BackStab script feedback?

I find people often making team fortress scripts and asking for backstab scripts i know i could have used math.acos and :Dot() function but i did not want to deal with radians. But i would appreciate some feedback on what i could have done better. I did not post this on the roblox forum because they always bash.

tool=script.Parent
sword=tool.Handle

sword.Touched:connect(function(hit)
 if hit.Parent ~= tool.Parent and hit.Parent.Humanoid ~= nil then

   humanoid=hit.Parent:findFirstChild("Humanoid")
   vCharacter=tool.Parent
   TorsoPos=hit.Parent:findFirstChild("Torso").Position   --the torso of the guy you're about kill
   vTorsoPos=vCharacter:findFirstChild("Torso").Position  --your torso
   Player=Game.Players:GetPlayerFromCharacter(hit.Parent)
   vPlayer=Game.Players:GetPlayerFromCharacter(vCharacter)

   if Player.TeamColor ~= vPlayer.TeamColor then
         humanoid.Died:connect(function()

             local distance=vTorsoPos-TorsoPos 
             local direction=distance/distance.magnitude 
             local dp=dotProduct(normDistance,humanoid.Torso.CFrame.lookVector)
             print(dp)

             if dp  < -0.1 then   
           
                 --increase the value to increase the range
                 -- but don't make it 0 or greater 
	         local m=Instance.new("Message")     
                 m.Parent=game.Workspace            
	         m.Text="BACKSTAB!!!"               
                 wait(2)                            
	        m:Destroy()     
                         
             end
         end)
 end
       
      end
     end)

First: tab your code correctly. This isn't super hard to do, and it makes code much easier to work with.

Next: use local variables. It's always a good idea to declare your intent by explicitly declaring variables using local. It also saves headaches later.

Make your code much easier to read by putting spaces around operators. At the least, spaces around = and + make it significantly easier to parse.

distance is a poor name for a displacement

normDistance is a poor name for something that's always length 1 -- call it a direction.

dotProduct is superfluous. Just use direction:Dot(humanoid.Torso.CFrame.lookVector)

Use the two argument Instance.new(class, parent) to save a line.

Use workspace instead of game.Workspace.

Use :FindFirstChild instead of :findFirstChild.

EDIT:

• hit.Parent.Humanoid will never be nil. You will get an error if the object doesn't exist. Use :FindFirstChild("Humanoid") instead.

• It's pointless to use :FindFirstChild("Torso").Position. The value of not erroring when the torso doesn't exist goes away if you try to ask for the .Position of nil. Just use .Torso.Position, or do proper error checking like it sounds like you need.