A thesis statement lets your reader know early on exactly what your essay is going to be about, and it also keeps you focused on your essay's main point. A thesis statement should be very clear as it announces your topic and your point, and limited in scope, so that writing your essay is a managed task. Most often, thesis statements will be either argumentative or explanatory in nature. A good thesis is restricted, almost bite-sized. The world is a terrible mess.
Old age has many difficulties.
Crime must be stopped. A good thesis is concise. Arizona's new health program is excellent, but it has several drawbacks, and it should be run only on an experimental basis for two or three years. Arizona's new health program has several drawbacks. A good thesis is specific, not vague.