Identify the symptom that is present now.
Say whether water spills from the edge, escapes at a joint or backs up beside a downpipe. Include whether it happens during ordinary rain or only a heavier downpour. Visible leaves and growth can be reported without reaching into the channel. Moss pieces may be part of collected debris, but clearing them does not mean treating the roof. A stain may remain after an earlier overflow and is not by itself proof of a current blockage.
Identify any section that was not attended to before, alongside the location of the present overflow. A completed front clean does not explain an untouched rear run. Keeping those locations distinct helps avoid treating another cleaning as a repetition of exactly the same task.