Update compat function docstrings

[tockards]

Adds docstring to new function added.

Definition of Done Checklist

• [x] Code meets our python style guidelines?
• [x] Unit tested (coded, passed, included)?
• [x] Requested at least 2 reviewers?
• [x] Commented code, particularly in hard-to-understand areas?
• [x] Made corresponding changes to the documentation (e.g. Python documentation, System Engineering Documentation, version description updates, README file, etc)?

JIRA: MT-1121