The answer to the question "Is my essay good?" is largely subjective and depends on your own goals for the essay. Ultimately, you need to be the judge of whether or not your essay is good. There are, however, a few things you can do to help ensure your essay meets the criteria for an effective essay.
For starters, be sure that you have followed the instructions given for the assignment. If the essay requires a specific format, length or topic make sure you have followed all the guidelines. Spending a few extra minutes to double check your work can save you from a potential bad grade.
You also want to make sure that your essay has a clear introduction and conclusion. The two should be related and create a cohesive story. The body of the essay should contain supporting evidence and should follow a logical flow. Finally, be sure to proofread your work for any typos or grammar errors.
Overall, only you can truly answer the question "Is my essay good?" But following these tips can help ensure that your essay is as effective as possible. Take time to review your work and use your own judgement to decide if your essay is meeting your goals.