I think this was brought up before. I'll explain why we don't have a page for that:
1) The skill name, those we have are made up by eAthena or took from Aegis. Like Wind Element Attack etc ... some of them are self-explanatory anyway while others are harder to understand but we don't have choice.
2) There are no description for those skills, what you see in game is what you get from the skill. Because they are made for server side use only, no player are suppose to use npc skill so the description can't be find in the client files.
So we don't have enough information on npc skill at all.