Reduced tolerance is definately another indicator that his condition has worsened.In my drinking prime I could down a quart of overproof rum before pushing back from the table but in the latter days one bottle of beer was enough to intoxicate me.
Your husband already knows that something is amiss in his drinking, what he may not know is that his condition will only worsen if he does not seek out the help of AA or some other alcohol treatment facility.
As a concerned spouse the best you can do is help to enlighten him as much as you can about the treatment of alcoholism and encourage him to attend some meetings.
Take care of yourself.Sounds to me like you already understand much of what you need to do.