Let us help you produce the most effective cover letter possible. The letter will argue that your manuscript is a good fit for the journal you are submitting it to and highlight your most important findings.
Ultimately, your cover letter is designed to influence the decision of the editor to send your manuscript out for peer review. The letter is far from just a formality and should be written with the same care as your manuscript's text (if not more).
The cover letter accompanying your journal submission is your chance to lobby on behalf of your manuscript.