As suggested here: SlimeKnights/TinkersConstruct#4967 (comment)
It would be nice if mods would be able to apply a container tag rather than needing to include Mouse Tweaks as a dependency. Support for Tinker's Construct is partially broken without this.

Hm, does @MouseTweaksDisableWheelTweak really require Mouse Tweaks to be loaded at runtime? I've seen a few mods use it, surely they wouldn't if it required Mouse Tweaks... That said I honestly have very little idea how to do this properly (or what a Container tag is) so maybe there's some example I could follow and some test mod with which I could test that I got it right?

I cannot see how adding an annotation to a class would not be a runtime dependency.

As far as what a container tag is, any registry in minecraft supports tags. Its just like a block tag or an item tag, but on the container registry. Find the registry closest to the container screens and use tags from that.

I cannot see how adding an annotation to a class would not be a runtime dependency.

The idea was to have an "api" type dependency with the annotation class, and at runtime Mouse Tweaks checks the annotation presence with reflection. I think a number of other mods also have "api" dependencies that don't require said mods loaded at runtime; it's entirely possible that I did something wrong though.

The mods that do that annotate a class used nowhere else in their logic (that is, that has no use without the mod the annotation is from). Not annotate a class that the mod cannot run without.

For example, JEI annotates a JEI plugin class, not my recipe class or my GUI