Say roughly when work was done and which runs it included. Describe leaves, small twigs or other debris visible from the ground and any repeated overflow. If nearby trees are relevant to what you have observed, mention them without assuming they explain every drainage problem. A past visit gives context, but it cannot establish the current condition inside all channels.
Show the front, rear and any conservatory roofline in safely taken photographs. Say if one corner fills sooner than the rest. Planning another check should consider these observations rather than turning a previous interval into a guarantee that the system will remain clear until a set date.