When I enlarge your photo,, I see a tiny caterpillar or similar tiny critter crawling along. The round spots suggest that earwigs may also have a taste for your sage plant. Several things you can do: first, remove the plant in its pot from the outside pot--- water collecting in the pot as well as dropped leaves, etc. are very attractive to pests. Second, put the pot in an area that is isolated from other plants ( it ooks like it is currently in the middle of  another planting). Then you can "clean=up" the litter in the pot :the  oldest sage leaves (the gray mass around the bottom of the plant) should be carefully detached. You can give the cleaned  plant a spray with water to knock off any crawling insects or worms from the leaves. I'd also suggest removing any leaves that are badly chewed. If in this process you find any earwigs: dampen a newspaper page and roll it up. Set it next to the plant in the evening and the next day, pitch the roll into the trash,(Do not unroll it or if there are insects they will just fall out and run away.) Hope this works for  you!