TLDR: write metadata information in your python toolbox in markdown and generate XML from it.
Wanted to share a helpful tool I’ve created for python toolbox metadata. The goal is to store the entire structure of a project as self contained as possible, including the metadata.
This led to me coming up with a tool to store and generate the metadata from a combination of arcpy Parameters and a custom dictionary, written as markdown strings in python.
A nice side benefit is it lets you incorporate HTML elements not supported by default, such as code blocks.
Hopefully someone else finds it as useful as I have!