I assumed you'd build such a massive set of rules (that claude often does not obey) that you'd eat up your context very quickly. I've actually removed all plugins / MCPs because they chewed up way too much context.
It's as much about what to remove as what to add. Curation is the key. Skills also give you some levers to get the kind of context-sensitive instruction you need, though I haven't delved too deeply into them. My current total instruction set is around ~2500 tokens at the moment