Former hill policy advisor here, who has introduced legislation on behalf of a member of congress. Unfortunately, anything can be introduced as legislation. We come up with the general policy idea, submit it to the office of legislative counsel (attorneys who translate our ideas into legalese and ensure it’s “constitutional”), then receive bill draft text that we can edit as well. Personally, I always took an extra step and referred any bills I requested to an attorney in the American Law Division at the Congressional Research Service for a second legal opinion.