Yep thats true pre grounding is very much worth it, if you just feed the agent a quick environment brief upront instead of making it spam tool calls to figure out where it is, you save a lot of tokens.
I have built some agent system to analyze the prod env from my and and web project when i had prod issues, so i had a agent in the env asked this thing and it told me the kubectl command with 0.99 confidence, well it was completely wrong, so ready-only for PROD systems should stay