Whenever I use my sword, both the toolslash animation in workspace.(PlayerName).Animate.toolslash and the animation I have playing using the sword's script play almost simultaneously. How do I prevent this?
It sounds like the animation you're trying to play has a low priority.
To fix this, open the roblox animation editor, select Edit, Set Priority, and change the priority to Action(since this is an attacking animation). Make sure you export the animation afterwards to save the changes.
This is the only thing I can imagine would be interfering with your animation based on the little information you gave us. Hope this helps.