Heal: Anatomical Training. When you need to know about the anatomy of a creature, how injured it is, what effects (such as poison) are currently acting upon it, or what weapons were used to kill it, you can make a Heal check of DC 15 to determine these things. The GM should add to the DC for unusual weapons or circumstances, such as a +4 when wounds were caused by an exotic weapon.
Powerful effects with skills that normally don’t work in this manner. I believe that harsh modifiers to the DCs, as above, are needed to balance out the fact that the PC’s are getting some important utility out of skills that they don’t normally have.
However, these new uses give the players something important to work toward, and remain useful late in the story!