The best SEO friendly page titles must represent the product or service in question. It must be not more than 70 characters including empty spaces. The description/summary which is SEO friendly must tells vividly about the title above and the best SEO description must be not more than 160 characters including empty spaces.
-The title is 70 characters including empty spaces
-The description is 160 characters including empty spaces
product or service title which is around twenty words (20) and not more than 160 characters.
Product or service long description or details that tell about the title above
The whole content of the product or service with any amount of words but advised not too long. About 200 words can satisfy the details of the product or services unless otherwise you attach the product manual to the website or break it to several pages.