I really like Adam Jones for his potential and his all-around skills. This season stands to be a real breakout for him. Thus far, he's been living up to the hype. Look at the season numbers:
.324 avg, 12 HR, 41 RBI, 44 runs scored, and an OPS of .938.
Remember he was the key piece in that trade for Erik Bedard last year. So big things have been expected of him (as you can relate). Still, if you are looking to shake things up on your roster, that is the way it goes. You are right to question his consistency of course. I know he's slightly banged up right now (a shin injury) but keep an eye on that, and maybe give him a chance if you can afford to wait.
That outfield you have is pretty good without Jones, between Lind and Ichiro at least. Your infield is top notch, really. Testing the trade waters is never a bad idea, and maybe look for a sold pitcher.
Otherwise be patient and see that maybe Jones is going through an injury more than slump. I don't think he has hit a wall by any means, given his experience at this point. Make sure you see who else you can add in the OF to not miss a beat. But a trade is always a good indicator of deciding to keep or release--I would hold out for a really great offer.