I found a comment on one of the videos in the Khan Academy site, which is something along the lines of...
Always err on the side of giving too much information.
(The subject was maths, and the poster's English seemed idiomatic enough.)
I'd parsed the above as:
While writing an answer to a maths problem, you're stuck between the choice of giving or not giving some information. Your answer could be either "lacking" or "have unnecessary/more than required info" if you choose to go with any one option. Either way you could make a mistake. But it's always safer to go with the latter (option). At least you've included all the possible information you can. So it all boils down to this — if you've to err, err on the side of giving too much information.
To my non-native ear, it doesn't sound immediately obvious. It might even be ungrammatical, but that doesn't seem very likely.
Is the sentence
- obvious enough to native speakers