If you are worried about why your toilet isn't working as well as it should be, there are several things that could be the problem and there are things that you can do that will fix the problem so that you can have a toilet that works with no problem.
The phantom flush isn't some ghost using your toilet and politely flushing it for you. Instead, what it is is water draining from the tank into the bowl, so it sounds like your toilet is flushing, especially when the tank is topping itself back off. If you notice that you have the phantom flush going on, it's pretty easy to fix. What you need to do is to look at your flapper. It's either not working well or it isn't seating itself properly. The flapper is the part of your toilet that lifts when you flush the toilet so that water can run down into the bowl from the tank. They are generally pretty easy to repair. Just make sure that you get your toilet completely empty before you do, otherwise, you are going to end up with water all over your floor. To make sure that your toilet is completely empty, you need to first turn off the water going to your toilet. Then flush your toilet. That will get rid of all the water in the bowl, and the water in the tank will flow down into the bowl. Flush again, and the tank will be completely empty and you can change your flapper.
If you have noticed that your toilet's flush keeps getting weaker and weaker, it could be because of hard water build up. A weak flush uses more water because you have to flush it multiple times in order to get everything to go down the drain. Now, if you really wanted to, you could use rags and wooden skewers up through the holes that allow water to go from the tank to the bowl, but that can be time-consuming and could be really nasty. There is an easier way to do it. You can make a very weak muriatic acid solution and use that to eat through the build up. It won't hurt your toilet, so it is safe. However, it will hurt you, so while you are using it by pouring it in the overflow tube of your toilet, make sure that you wear gloves, long sleeves, and eye protection. Keep a fan running as well.
You need to know that your toilet is going to work the way it should every time you go to flush it. In order to do that, you need to figure out what the problem is and how to fix it. Call a service for plumbing repairs if necessary.