Um, yes they willl tone your upper body muscles.
I also do isometric holds in various push up positions.
Get in the pushup position on the floor with your hands close together and your elbows in close to your body.
Lower down a couple of inches and hold it for 30 secs to a minute. You should be shaking
This will work the triceps, shoulders, chest and upper back. Experiment and try holding at different levels of the pushup position.
It's all good