One difficulty I had with the existing documentation and tools for DBAL was the lack of a reference for what the valid values were (e.g. "notnull" instead of "not null").
See http://docs.doctrine-project.org/projects/doctrine-dbal/en/latest/reference/schema-representation.html for example: some values are given, but there is no reference list, and anything put just in documentation would incur the risk of not remaining updated.
So I tried to guess-generate the information from the code, like this: https://gist.github.com/FGM/8261606 (also attached).
Unless an equivalent already exists somewhere, I think it could be useful to have something like this in upcoming releases.