I edited your question to reflect that what you are asking is whether the title of an essay should reflect the main idea of what is being written about.
All writing that is done for the purpose of informing, describing and persuading should take into consideration the main theme of the composition when deciding for the title.
The title should be concise, descriptive enough, and use key words that can be easy to find on a database. Moreover, the title should reflect the position of the writer if the work is going to be used for persuasion. For example, if you are going to write in favor of the death penalty, the title of this argumentative essay should reflect the position of the writer i.e, "The Death Penalty is a Viable Solution to Decrease Crime Rates".
On the other hand, if you are writing a descriptive essay, say, about how your graduation day was a disaster, the title should still reflect what the essay will be about, as well.
You can have creative license to write a title that is nor reverent to the topic when you create a piece of work meant for entertainment using figurative language, such as a poem, a fictional account, a fantasy, or something like it. For example, James Joyce is notorious for creating works using titles that have nothing to do with the work. You see that a lot in poetry and other experimental written works.
Yet, even then, writers prefer to keep titles attached to the theme to pique the interest of potential readers.
This means that the answer to your question is "true". The title should reflect the work in question and should be able to raise the curiosity of the potential reader. Read more about crafting effective titles for essays at our essay lab here on Enotes.