Drizzle olive oil over tilapia fillets and season with salt and pepper. Heat a medium skillet over medium heat. Add prepared fillets, and sprinking with lemon juice from one of the lemon halves. Cook for about 3 minutes per side, or until fillets flake easily with a fork. Transfer to a plate and keep warm. Add capers, tomatoes, juice from the other lemon half, and wine to skillet. Increase heat to medium-high to burn off the alcohol from the wine. Reduce to low heat and return fillets to the skillet. Add asparagus. Cover, and simmer for two minutes. Transfer fish and asparagus to a dish and keep warm. Stir butter in to the skillet. Bring to a boil and reduce to desired consistency. Remove from heat and spoon sauce over fish, and serve.