Some people will agree, some will say natural. The problem is there is no definitive way to prove it is or isn't a tool since it doesn't look like a typical scraper, knife, blade, or point.
I would say it's not a tool since there are no markings that prove it was altered. You could disagree and state your reasons and the never ending circle begins.
You can spend the time trying to force "non-traditional looking items" into the tool category or spend that time searching for items with that aren't questionable in the least.