Yes, best estimate is worthwhile. They're not going to call and check, and even if they did, what's the chance the person they talked to would actually be able to tell them?
Writing a paragraph is a good idea. Bullets are not to be trusted. The application sort of squishes all the fields together. I wrote mine like this:
RESPONSIBILITIES:
blahblahblah. yaddayadda. Dooodooodoo.
LEADERSHIP ROLES:
blahblahblah. yaddayadda. Dooodooodoo.
ACHIEVEMENTS:
blahblahblah. yaddayadda. Dooodooodoo.
And it came out like without the spacing, and with the text all wrapped:
RESPONSIBILITES: blahblahblah. yaddayadda. Dooodooodoo. LEADERSHIP: blahblahblah. yaddayadda. Dooodooodoo. ACHIEVEMENTS: blahblahblah. yaddayadda. Dooodooodoo.