The wiki describes how to choose among our asserts. Engineers chronically choose the wrong assertion style. The header itself has no documentation.
We could provide a link to that wiki page at a minimum and maybe that would help.

https://wiki.corp.mongodb.com/display/HGTC/MongoDB+Assertions+and+You

One problem with this is that the wiki is not accessible outside the company.

The much better and more complete solution is to write inline header docs in assert_util.h (and invariant.h), where the implementation can perhaps answer questions that the documentation may not address or may leave ambiguous. The inline docs will appear in IDE hovertext and be source-controlled and versionable.

We should also now be linking to the docs/exception_architecture.md document, which has a little more about the behavior of the different [[:alpha:]]assert facilities.