Cloud cover - Agrometeorological indicators

Hi everyone!
I have a doubt about how the parameter cloud cover is defined in the Agrometeorological indicators database. The documentation says that it is defined as “the number of hours with clouds over the period 00h-24h local time divided by 24 hours”, but I am not sure if cloudiness covering a small portion of the grid is considered cloudy or if the grid must be completely covered by clouds.
I’ll really appreciate your response, thanks!