Up To Snuff Meaning

(chiefly Britain, dated, idiomatic) Mentally alert, shrewd, savvy.

Example: 1945, "State of the Nation's Health," Time, 15 Jan.:
  About 40% of U.S. counties lack full-time public-health service. . . . Many registered hospitals are not up to snuff.
1846, Charles Dickens, Dombey and Son, ch. 31:
  "Dombey," says the Major, with appropriate action, "that is the hand of Joseph Bagstock: of plain old Joey B. . . . a rough and tough, and possibly an up-to-snuff, old vagabond."
1904, P. G. Wodehouse, William Tell Told Again, ch. 7:
  But the people, who prided themselves on being what they called üppen zie schnuffen, or, as we should say, "up to snuff," and equal to every occasion, had already seen a way out of the difficulty.