Cook pasta according to package directions, omitting salt and fat; drain. Reserve 1/4 cup cooking liquid.
While pasta cooks, heat a large nonstick skillet over medium-high heat. Coat pan with cooking spray. Add the garlic and zucchini, and sauté 5 minutes or until zucchini is tender. Combine pasta, zucchini mixture, and tomato in a large bowl, tossing gently to coat.
Combine reserved 1/4 cup cooking liquid, pesto, salt, and pepper in a small bowl. Drizzle over pasta, tossing gently to coat. Sprinkle with cheese.