If adding something to the context doesn't help, it's only proves you're not adding the right stuff.

I'm adding pointers to specification documents, and it saves me from the /new dumb coding agent that sees your code base for the first time and knows nothing about architecture, concepts, code organisation, etc...

I'm using no cookie cutter directives though (except maybe "do not attempt to deploy, we're using CI CD to deploy" to avoid an automatic "wrangler deploy" to Cloudflare)