1. Preheat oven to 350°.
2. Combine first 5 ingredients in a small saucepan; stir in 1 tablespoon vinegar. Bring to a boil over medium-high heat. Cook until reduced to 1/4 cup (about 3 minutes). Reserve 2 tablespoons agave mixture; set aside. Keep remaining 2 tablespoons mixture warm in pan.
3. Heat a large ovenproof nonstick skillet over medium-high heat. Coat pan with cooking spray. Add pork to pan; cook 5 minutes, browning on all sides.
4. Bake at 350° for 10 minutes. Brush pork with 2 tablespoons reserved agave mixture. Bake an additional 5 minutes or until a thermometer registers 155° (slightly pink). Let stand 5 minutes.
5. Add remaining 1 1/2 teaspoons vinegar, 1 teaspoon water, and red pepper to remaining 2 tablespoons agave mixture in saucepan. Cut pork crosswise into 1/2-inch slices. Drizzle glaze over pork.