Signifies condition or state generally, whether good or bad is usually determined by the epithet. Here Swift uses it in the sense of 'good condition'. So it is found in Tusser's Five Hundred Points of Good Husbandrie —
'Who abuseth his cattle, and starves them for meat,
By carting or ploughing his gains are not great;
Where he that with labour can use them aright
Hath gain to his comfort, and cattle in plight'
But Tusser also uses the word indeterminately, with a qualifying epithet.