Describe a corner, joint, long edge or downpipe rather than simply saying the roof leaks. Water may be noticed below a gutter without its starting point being visible. Explain what you can see from a safe position and anything you cannot. An existing photograph during rain can help, but no one needs to climb or stand under an overflow to gather information.
Include whether the symptom is recent, has returned after clearance or follows a known repair. Those details help distinguish the current request from an earlier assumption. A previous cleaning appointment is not evidence that a fitting is sound now, and a persistent drip should not automatically lead to another identical clearance booking.