A strainer is part of a drainage arrangement, and its condition should be included in maintenance observations. Missing or damaged components deserve review against the actual system. A replacement should fit the intended application.
What to do next
Ask the contractor to document the outlet and proposed component. Keep cleaning and repair records by location. Where recurring blockage occurs, investigate the source and maintenance approach rather than assuming a different strainer alone solves every issue.
Related Perkins guidance
Contact Perkins Roofing to discuss your roof and the appropriate next step.