Isolated Hilltop

The moment the dragon grips the sword, the dragon knows several things. One, it now owns the jian, and will continue to own it until somebody else grips the hilt. Two, it is now incapable of forgetting anything, so long as the dragon owns the sword- even if the sword is not being held or carried, or is kept locked in a vault miles away, even if magic is used to force the loss of memory (though certain powerful entities might be able to force it anyway- gods of memory, perhaps). Three, the dragon can will the sword to glow brightly; the light burns through deception and deceitful magic, and anything written down that the light falls on can be read and understood by the sword's holder, with the possible exception of very unusual and esoteric languages.

Four, the jian is a gift, and the dragon's use of the weapon will be observed and judged, and if the entity feels it is being misused, it will be taken away again.