There are hundreds of thousands of words that you can use to describe yourself. You are a unique human being and are in no way like any other that is why you have so much to tell about yourself. When you are asked to describe yourself, take into account the setting and the person you are talking to.
If you are describing who you are to someone at a party, tell them what your profession is and what you like to do after work. Keep it short and sweet.
But, if you are at a job interview, describe how you are in the field. What are the rules and the goals that drive you?
If you are asked to describe yourself and you are the kind of person who likes to get things done with hard-work, tell them that you work hard. Say something like; “I create milestones for myself and to achieve them, I can use all the energy in my body if I have to.”
Be honest. If you are not a hard-worker and fail to do things in time, change your habits, or be ready to face the consequences.