Thesis has main point and main idea and the argument you make should redirect this main idea and the sentence that captures on the main idea is your thesis statement.
Thesis statement should be well written and concise since it is the central argument of the document. It makes develop a thesis. Also, it is supported by evidence. Your thesis statement should claim an argument not because it is a statement of the fact or statement of opinion. It should be debatable meaning the persons should have different opinions on the subject matter. It can be accepted or disagreed. Also, thesis statement should narrow because it is more effective, if the topic is broad, more evidence is needed and it can be complicated.
Example of broad topic is “Drug is not good to our health”. It is not mention what kind of drug is all about since there are different types of drugs such as recreational drug, illegal drug, and medication drug. If it narrow down, it can be written as “Illegal drug is not good to our health”. Broad topic needs many questions to answer. Specific topic makes your thesis much more successful than writing about general topic that do not say much.
In addition, make sure that your thesis statement clear so that your reader or audience understand what exactly what you mean.