Protective dragon tiles were part of a broader defense against spiritual and political threats.

Evidence

The dragon on our roof tile was, in a sense, just a humble foot soldier in the great battle of the spirits that was being perpetually fought out at roof level, high above the streets of Kyongju. … But, at ground level, there were other threats: there were always potential rebels within the state – the aristocrats who had been forced to live in Kyongju, for example – and on the coast there were Japanese pirates. — Neil MacGregor, A History of the World in 100 Objects, 778

Categorization

• corroborated: 2 independent passages support this claim — Neil MacGregor, A History of the World in 100 Objects, 778