UntitledGoose

Hey I am trying to do a script where when you right click, it shoots a fireball. I would like to add a 30 second cooldown to it, but It won't work. Could you explain to me why? here is the script: 

on right click:
    if player's tool is  diamond sword:
        if colored name of player's tool is "&cFire Sword":
            shoot fire ball
            cooldown: 30 seconds
            cooldown message: &6Please wait 30 seconds!

It says I does to understand line 5 and 6.