[X] Mostly cooperate. Buffy tells them stuff about the summer's events that the average person in her organization would already know, and fills in context where appropriate. Most relevantly, Buffy briefs them on the Mok'tagar situation and her plans for resolving it, hoping they might actually be able to help somehow. However, any mention of Buffy's status as a Successor to an Old One and anything tangentially related to it is avoided, including the Wilkins dreams, the Lachrymal Artifact still unfound beneath City Hall, and the worrying indications of an upcoming dimensional merger.
[X] Stonewall the Watcher's Council. Buffy tries to avoid revealing any information she doesn't have to, including even moderately sensitive subjects like the Initiative, Faith, Harmony, and the Mok'tagar. It's likely that they'll eventually find out most of it eventually if they poke around long enough, but there's no point in making it any easier for them. In particular, Buffy doesn't want them messing with the attack on Mog'tog'og in two days.
[X] Tell them everything. Buffy fills the Watcher's Council in on all relevant topics, not just looking for help with the Mok'tagar but also with finding the Lachrymal Artifact, understanding her new powers, and dealing with the thinning dimensional boundaries. While they've had their differences, they're all mostly on the same side, and Mary's presence could indicate that they're willing to give some ground. In this option all the very most sensitive information will only be shared initially with Travers and Mary unless stunted otherwise.