Assuming you mean "headline," as in copywriting, you've come to the right forum.
SEO Workers Test For Five Key Skills
...Does your Seo Work pass this test?
It really depends. SE 'bots read header tags. Humans respond to headlines which promise a benefit. Copy has an important job -- convert the traffic that gets to the site. Traffic is only half the job, conversion is the other.
Content -- as in this is the Content Discussion forum -- is balancing the needs of 'bots and humans. With copywriting, your headline has one job. The job of a headline is not to "sell," or be a self-contained statement of logical fact. The job of a headline is to get the the first few sentences read.