To avoid any injuries your toes need to be free. Constricted toed give room to injuries such as bunions which can be very painful and sometimes debilitating.
Make sure there is at least the length of the index finger between your big toe and the end of the shoe.
This will make the shoe more comfortable when you walk or go about your business. A properly fitting shoe should fit snug around your heel and midfoot and leave some wiggle room in the front.