If you don’t want to know anything beyond the bare minimum… then yes the Canon 100mm macro lens does work with Sigma’s MC-11 adapter.
Read on for some more information though…
A reminder…
Sigma’s MC-11 adapter was not built for use with Canon branded lenses. It was specifically made to allow Sigma’s Canon EF mount lenses to be used on Sony camera bodies. Sigma does not recommend or guarantee that the adapter works with non Sigma lenses.
Autofocus
I do not know why, but I can reliably autofocus at ALL apertures while using the adapter on an A7 II camera body. From f/2.8 to f/32…
Autofocus is slow, but that’s true with all lenses when using the adapter.
You can speed things up by manually making big movements yourself and then letting autofocus dial it in. It’s a very effective method, with only the fastest moving subjects being out of your reach.
Fit
The lens fits snugly with the adapter, like it’s supposed to, and because of its relatively lightweight actually feels pretty good on an A7 II body.
Drawbacks
There are only two serious drawbacks in my opinion.
The autofocus speed simply is not fast enough to capture fast moving subjects. A native lens, like the Sony 90mm Macro, is really the only way you’re going to get those fast moving subjects photographed.
And the second is the way that the Sigma adapter does center-point autofocus. It’s genuinely a crap-shoot… A crap-shoot… Inside the center point. Your autofocus has already been limited to that center point, but the adapter can narrow it down even further… with only a single little square in focus. It can be frustrating and may require you to shoot the same picture a couple of times.