Describe the channel once
The niche field is a plain sentence, not a category dropdown, because it becomes the search behind every scan. “Hollywood casting news, breakups and red carpet drama” is a good niche. “Entertainment” is not — it matches everything and therefore ranks nothing.
Then add five to fifteen specific keywords. Rare words like x-men, oscars or a named person do real work; a word like movie matches half the feed and the scoring engine will discount it automatically. Finish by choosing a language, a region and the news sections you cover — sections also pull in the top outlets for those topics.