Actually, toolchain, ds-runtime and framework images are sort of deprecated.
This was the way we were manage images about one year ago (Legato 16.01.* versions).
The issue was that for pure command-line use case, it was too complicated to setup all the containers to make them working together.
We’re now working with sdk images, that are baselining all the necessary stuff in one image.
What you have to do is:
docker pull legato/sdk:16.10.1-wp85-wp750x-201701091127
This will download the lastest SDK version for WP85.
docker run --rm -it -v $MYPATH:/shared -w /shared legato/sdk:16.10.1-wp85-wp750x-201701091127 /bin/bash
This will start a bash shell inside the Legato SDK container. You will have everything set to play with Legato tools (mkapp, etc…)
$MYPATH needs to be a path on your host, that will be shared with the container.
Hope this will help.