Describe the corner before calling it a leak.
Leaves can gather at a bend or around the outlet. Water may spill over the edge when the route is restricted, while a failed joint can allow it to escape without a debris blockage. Note the place and timing of the water, including whether the main house gutter above also overflows.
Small roof fragments may collect in the channel alongside other debris. This does not make roof cleaning part of the job. If there are marks on the glass or wall beneath, show them as an observation. A stain alone cannot identify which connection, channel or roof surface needs attention.