WASHINGTON -- Chiding companies such as Jimmy John's and Amazon.com, Senate Democrats introduced a bill Wednesday that would forbid employers from requiring low-wage workers to sign noncompete agreements, a practice they said locks workers into their jobs and depresses wages. The bill, called the Mobility and Opportunity for Vulnerable Employees Act, or MOVE Act, would bar noncompete agreements for workers earning less $15 per hour, and would require companies to inform job-seekers ahead of time if they will be asked to sign one.