If you also ensure the AI writes relevant (and correct) docs, and also code comments and commit message, then I agree there is not much need for extra info, e.g. prompts / session distillation. I am not sure that that is the case currently (though we might be getting there soon at least in some cases).
Agree with this, I've been testing how AGENTS.md and similar can do to automatically have these behaviours and I feel (it's just feeling) it's been improving over time. Clearly depends a lot on the agent, the model, the codebase size and so on.