The king is good, fair, strong, and completely benevolent. He is ever-trusting of his people, and he can supposedly tell a good soul just by looking at a person. In this way, his land is fair, his people are happy, and his kingdom is peaceful.
Why this can be bad: A lot of people seem to think that just because a king is a good person, he is also a good ruler. However, a kind person does not necessarily have good political sense. The trope of the kind king comes up most often in Disney films and more generic medieval fiction. The first example to pop into my head is King Mickey from the Kingdom Hearts series. The fact that his kingdom is still standing amazes me. He’s a good person (mouse?), but he doesn’t really seem involved in politics at all. Honestly, Ansem should have kicked his ass, because he was more politically aware than any of the other characters. But the kind king trope prevails. He “rules justly” and “keeps peace,” though the stipulations of those sentences are never laid out. However, kind and honorable people are very easy to take advantage of, so unless your king is also a good politician (or has some politician friends to help him keep his head), his kingdom, even if it’s peaceful, might not necessarily be good for long.
How you can fix it: If you’re looking to make your kind king realistic, remember that there is more to ruling than personality. A king must have wise councilors and good standing, and a brain would help, too. Even then, if he wants to survive, he’s going to need to be wary of usurpers and manipulators, and he may occasionally need to make hard decisions that challenge his kindly inclinations. Ned Stark from A Song of Ice and Fire is a great example of this. He was not only a kind and honorable man, but a good tactician with intelligent people helping him. However, his honor and attempts at kindness are what get him killed. It’s important to think about how your character’s personality intersects with his position of power, and the way your character reconciles the contradictions is what will determine if he lives or dies — or if he’s even a believable ruler to begin with.
Bottom Line: If your king is too good, too trusting, his head is going to end up on a chopping block. Make sure he can reconcile his kindness with his politics, or else you may have to kill him.