an update to my answer: Databricks has advised us that the `dbutils.notebook.entry_point` method is not supported (could be deprecated), and the recommended way to read in a job parameter is through widgets, i.e. `dbutils.widgets.get("param_key")` (similar to Task parameters -- if you have a Task param and Job param with the same name, the Job param value takes precedence). 

If you want to read a dynamic value reference like the run_id inside a Notebook, you can set the reference (e.g. `{{job.run_id}}`) a Task or Job param, and read it like a widget.