Agate is protective, healing and stabilizing. It comes in many colors and varieties, some of those colors represent other properties such as blue lace agate, moss agate and carnelian. So depending on which kind of agate you are using, you may want to check those descriptions as well.
All agate do have similarities in which they are all strengthening and grounding. Agate can also help you connect further with the earth.
Agate is said to cure insomnia if you place it under your pillow as you sleep, it also works to relieve stress and raise energy.
Agate can help to ground and stabilize emotions therefore it is helpful for agate to one that feels unstable in the emotional department.