Answered by Steve, Hiring Expert at Caterpillar Inc., on Friday, December 6, 2013
I would recommend that you always provide some information in this area. I don't feel that it is necessary to write a long, detailed cover letter, however, a short and concise note is appropriate and shows that you have a legitimate interest in the job. In this note be sure to express your interest in the job, being sure to list the specific job title (and in some cases requisition or job number). Also, include a comment along the lines of how you feel the position is strong fit with your career aspirations and how you look forward to learning about the next steps. That is sufficient for this part of the on-line application process. It shows you are detail oriented, as you did not overlook any part of the application process and have a strong interest in the position.