If you could, can you checkout the [numpy docstring format](https://github.com/numpy/numpy/blob/master/doc/HOWTO_DOCUMENT.rst.txt#method-docstrings). Basically

```
argument: type
    description
```
If they're optional you can note that on the type line after a comma. Put the defaults in the description. In the description we put the argument names (like `ax`) in double back ticks so they render nicely on the website.