I smoked my first brisket yesterday on my new Traeger. The brisket was small, 2.3 lbs (most recipes call for a six lb brisket, but there are just two of us). I was using an internal temp probe for the meat that I could read by pressing a button on the Traeger. I started it on smoke for the first 2.5 hrs, then turned it up to 225 degrees. About every hour I hit it with some mop spray. After two more hours (4.5 total) it came up to 160°, I put it in a metal pan, put some of the mop sauce in the pan, covered it with foil. I also turned the temp up to 275° because it was 45° outside and I thought it was going to take forever. After another 90 minutes the internal temp was 200° and I took it off, wrapped it in foil for 15 minutes to rest while we got the rest of dinner ready.

It had a beautiful smoke ring, wasn't dry but could have been juicier, had nice flavor but was a little chewy. So what did I do wrong? What was/were the fatal flaw(s) in not getting a tender brisket?