Google and other search engines always want to offer the most relevant content for a specific search result. The relevance of content depends on many factors. Different researches shows that the number of words is an important factor. Read this article about the ideal content length for SEO.
In Textmetrics we determine the number of words based on an algorithm, in which we take the given keyword in account. Also, in Textmetrics you have the possibility to work with an SEO rule set which is less strict in the number of words on a page. The ruleset option allows you to choose between a blog/article- and productpage ruleset. Read more about this rule set (also called: text type).