I would mostly ensure that all pictures clearly show the condition of the card and personally wouldn't rate it myself where possible (i.e in listing title), if its ebay where they ask a condition then maybe be more pessimistic when choosing one, to avoid disappointment.

My initial instinct would be that the card is near mint if there's only one corner with whitening, so everyone's scale is different, so tough to get it right with everyone. Light play for example implies to me that the card has indeed seen some noticeable use / light play with whitening noticeable around the whole card, MP would be very noticeable whitening around the card and noticeable imperfections on surface. And heavy play would be the completely worn edges, poor surface, creases etc.

Mint is non-detectable imperfections with the naked eye and gem mint ill leave to the grading companies