Cook tortellini in boiling water 8 minutes. Add asparagus, yellow squash, and zucchini to pasta; cook 2 minutes. Drain pasta and vegetables, reserving 1/4 cup cooking liquid.
While pasta cooks, heat a large nonstick skillet over medium-high heat. Add tomatoes, pesto, and garlic; reduce heat to medium-low, and cook 1 to 2 minutes or until thoroughly heated, stirring constantly. Add reserved cooking liquid, pasta, vegetables, and basil; toss. Sprinkle with cheese.