In your profile’s services section, Google may offer predefined services for your category, and you may be able to add custom ones. If your category has a predefined list, start there and select every service you really offer.
Sterling Sky, a local search agency that publishes its tests, reports that “Services impact ranking,” and adds that “The ranking impact seems to vary based on the industry and market.” Their test covered predefined services. Then add custom services for anything you do that the list misses, each with a short, plain description.
One more reason to keep the list complete. When a customer reviews a service business, Google may ask them which job you did, and those job types come from your service list, your website (if available), or a standard list of tasks based on your business type or other authoritative sources. If a job you do is missing, add it to your service list so customers can pick it.