Originally Posted by
corrado33
If it works and it looks straight, you're fine. Make sure the derailleur limit screws are set and ride away. There's nothing wrong with "bending" it by hand except for putting undue stress on the derailleur itself. Again, if it works, you're fine.
Campag is right.
Your chances of getting it aligned correctly without the tool are pretty dismal.
Yes, I would bend it back by hand in an emergency, but it still needs to be checked and correctly aligned at the earliest chance.