The bit you've bolded is the key here.
It could - and arguably should - be worded differently such as to get the word "characters" in there somewhere, but consider the ramifications of these two alternate wordings:
"The players describe what they want their characters to do."
"The players-as-characters describe what they want to do."
The first promotes pawn-stance, the second promotes immersion. The wording they actually used promotes neither, and thus leaves it open-ended. For a game trying to be the biggest tent it can, this is an impressively good little piece of writing in terms of achieving that goal.