The current patch description format is the commit message.

The new patch description will be the following format:

Commit Queue Merge: '<commit message>' into '<owner>/<repo>:<branch>'

Multiple modules are supported as follows:

Commit Queue Merge: '<commit message 1> <- <commit message 2>' into 'owner/main_repo:master'

This description comes from the evergreen client executable and since we can't force a client upgrade, the validate client must support both formats.