Tools like lighthouse compare your website to thousands of others and tell you how you're doing in terms of performance and accessibility. Rate my copy does something similar, but for text. We compare the words on your landing page to thousands of startup websites and tell you which meaningless, empty phrases you all use.
The grades are from A (very original) to F (you used every cliche in the book). The top cliches are shown, but the score is based on more than just those.