Agree with comments from Loge and Spoffy.
In addition, context can be important in determining if a definition indication is ‘fair’. For instance if the wordplay is complex or unusual then the definition indication should ideally be more straight forward, and vice versa. However, too many generalised definitions in the context of the entire puzzle can be frustrating, especially if such clues cross each other.
In addition to DBE, it might also be considered fair to include indicators for archaic words, American usage or unusual spelling variants etc.
The EGYPT clue would be very difficult in isolation but the fact that the comparatively straightforward HUDSON BAY clue gave the central Y made getting to Egypt a little easier. (I personally don’t think that Egypt can be described as a realm, perhaps 'ancient realm' would be ok but it wouldn’t fit into the word play. Also as GYP is a fairly unusual synonym for anguish the clue becomes less solvable).
A similar example of a general definition pointing to a specific country is:
Country with its capital in Czechoslovakia (6)
Here, however, because we have Oslo in the clue there is no ambiguity in getting to NORWAY.