Option to control the TOC text for specific anchors

Sometimes I don't want to display the full heading of a section in the table of contents. Is there or could there be an option to override the heading display?

Example: currently in the Reductio README (https://github.com/esjewett/reductio), one heading is "reductio.avg(boolean|value)". I would like this to be the heading, but in the TOC I'd like to display only "avg".