[thejeff]

If you assign a mage to cast a site search spell as a monthly ritual (Shift-M), he will pick a new province to target every month.

As I understand it, he picks the first province that, when he chooses his new target, is owned by you and not searched yet. There are two problems. The most obvious is that it doesn't consider provinces that are already being targeted this month, so only one auto searcher can be used per path.

The more subtle is in that "when he chooses his new target". This is done during the ritual casting phase, apparently right after he casts.
If other mages are also using that searching spell, targeted manually, they may or may not have cast already. Thus a province searched later in the turn may be targeted.
Also, since battles occur after the new target is chosen, provinces conquered that turn are not considered and provinces lost can be searched.

Whatever is being used to determine whether a province is a capital seems broken as well. Some capitals are searched, some are not. Sometimes non-capital provinces are skipped for no apparent reason.

All told, it's still worth using, but I hope it can be fixed.