They're only as good as the information that you find and type into them. If/when you type faulty information into the citation helper, then the tool will create a citation with faults/mistakes. This is true, also, of the citation tools provided in library databases like ProQuest--a computer algorithm assembles the citations, and they'll often have mistakes in them.
Here's a citation tool you can try to use, but take extra care in your spelling and capitalization! Plus be confident that you're identifying the author of a page correctly, as well as the title of the source page/article versus the title of the source website (they're usually different!).
EasyBib for web pages (MLA)