Yes, if a buyer puts an offer on the your house and comes represented by a buyer's agent, then you will pay the Buyer's Agent Commission (BAC) at closing. When Sage's MLS and Listing Broker Service Provider reaches out to you to provide you the MLS Listing service, you will fill out paperwork that requires you to choose how much you are willing to to pay for a BAC. It is highly recommended that you set this commission in the 2.5-3.0% range. Otherwise, you will drastically limit the number of buyers represented by buyers agents that will be interested in coming to see your house and you will make it harder for you to sell your house.
If a buyer comes and makes an offer on your house without a buyer's agent. Then your Sage Listing Agent will aid in creating a contract for you and you will not need to pay the BAC, but this is less common, but still a possibility as most buyers will come with an agent to help aid them in the process of buying their house.