Watering Foundation in Texas

Edit: Moderator: Moved from General

I live in North/East Texas. My house is 4 years old. I have an automatic sprinkler system. At closing, I was told that was not adequate for keeping my foundation moist. I have several sprinkler heads along the perimeter of my house. Would it be suffecient for my fondation if I replace some of the heads with 360 degree sprays along the outer walls to keep the ground moist along the wall? I went to the hardware store to get some 360 degree heads, and the employee suggested not to do this. Would it be better if I buy a soaker hose for this, or will the sprinkler system be enough? The current heads spray 180 degrees so the foundation should be getting some as it is. Thanks.