A good first pass is as much about the ability to pass accurately as it is to make the right decision with little to no risk of giving it up to the opposition when the responsibility of the first pass is yours to make throughout a game. A combination I think we can agree not all Dmen are consistently able to pull off around the league, some guys will drive offense but their first pass is a Russian roulette of outcomes throughout a game. Some guys will be hard on the puck, win their battles and chip it off the boards playing the whole game almost like its a PK, very rarely making a heads up play out of his zone. Some guys will go win their battles, and before they even reach their blue line, make a heads up play of passing the puck to a team mate with high efficiency and low risk. The latter category is where guys like Weber and Chariot fall into, they don't drive offense, but they are very efficient on their half of the ice, and their good first pass allows them to support a healthy transition game.
Defensive Dmen with a good first pass are an essential part of a balanced D corps in today's NHL, imo. If you mesh them with offense driving partners who can skate up and down the ice, what you get is a combination of forward support, very good transition, and lowered turn over totals while that duo is on the ice.