Earlier Shog posted this answer over on MSO about "Help the helpless with how-to-ask tag tips". Fortunately, he didn't use the suggested interface:
But instead did something a bit more in line with the style guide.
I've gotta say, I really like the possibilities this has. I'd like to put it on a bunch of tags - both for help asking and for warnings.
Those warnings got me thinking... could we identify the tags beforehand as being problematic ones, and in the event that no tag guidance is provided if the tag has a closure rate above some threshold (50%? 75%?) a canned warning is displayed in this area:
The tag {name} has a significant number of closed questions. Please look closely at your question and consider if it is asked in accordance with the [help/on-topic] that is available on this site.
This could be run on a periodic basis and used to populate the guidance text in the event that no other guidance text is provided (rather than trying to pick it up on the fly).