Yep, it is an ability you cast on one mob, and this mob will not aggro you (lose aggro).
The ability as a recast timer of 10 minutes, however.

Yes, I agree that an MP-based ability casted on urself would be interesting. But since SE is planning to add a stealth skill I assume that they have something in mind that will address this. Hopefully that skill will be implemented very soon!! :-)