Cook pasta according to package directions, omitting salt and fat.
Drain; stir in tomatoes, 1/4 teaspoon salt, parsley, and 1/8 teaspoon pepper. Set aside and keep warm.
Combine remaining 1/4 teaspoon salt, remaining 1/8 teaspoon pepper, and flour in a large shallow dish. Dredge fish in flour mixture. Melt 1 tablespoon butter in a large nonstick skillet over medium-high heat.
Add fish to pan; cook 1 1/2 minutes on each side or until fish flakes easily when tested with a fork or until desired degree of doneness.
Remove fish from pan; keep warm.
Add wine, juice, and capers to pan; cook 30 seconds.
Remove from heat.
Add remaining 2 tablespoons butter to pan; stir until butter melts.