It can be a bit confusing because the system is really trying to communicate a lot of different things, some of which are
actually meaningful and a lot that isn't. Stat sheets trying to both be roleplaying guidance and tracking hard numbers is hardly unique compared to other RPGs, but in SDs case the hard numbers existed for 20 years before the current roleplaying guidance was brought in and you can tell that SD really started more as an RP-lite roll-for-everything hard stat focused experience and grew into more of a freeform RPI experience later.
The effect being that Judicious is Judicious not because a character now has the capacity for judiciousness where they lacked it before, but because Judicious starts with a J which is the letter grade of their stat, and the definition is just the literal dictionary definition of Judicious not necessarily the intent of that rank. Even the letter grade is itself really an abstraction of the actual value which is the number of raises made to it, divided at random between two (mostly) hidden substats at a few percentage points of variance.
Which is to say that the descriptors work okay in isolation in distinguishing between terrible and okay and good, although as Quotient mentions the sizing guidelines are even better (and fairly accurate too in my opinion) but the descriptors probably shouldn't be read into too too closely beyond that. A character with Dexterous agility is definitely dexterous, but also very reasonably would a character with Expeditious agility also be considered practically dexterous in roleplaying terms.