Here are some slightly different numbers I found in SEO resources:
Title Tag: should be between 10-12 words, more will be truncated
Description Tag: between 12-24 words
Keyword Tag: between 0-48 words
Page Heading Tag: b/w 1-57 words
Body Text: make sure it sounds natural, b/w 250-20,000 words
Brad
http://www.text-to-art.com