Tool dice don't score points on their own, but instead work to turn Hazard dice positive.
The pickaxe and shield faces on tool dice reverse the scores of particular hazards, making them positive instead of negative. Pickaxes make cave-ins positive and shields make dragons positive.
A single pickaxe turns all cave-ins in the same trove positive, and a single shield turns all dragons in the same trove positive.
Multiple pickaxes and/or multiple shields in the same trove have a multiplying effect on the hazards they counteract. For example, a player with two pickaxes and four cave-ins scores eight points (2 × 4).
The chests on tool dice don’t score points. They’re used in the Replenish Phase to cache dice results.