Not a security researcher, but this is IMHO obviously positive that the other side of the arms race is also getting stronger, and I would argue it's stronger than on the bad guys' side, due to the best being somewhat responsible and adding guardrails.
I believe cloudflare tries to work around that with Code Mode, right? https://blog.cloudflare.com/code-mode/ (but the OP is still useful for when classic MCP is needed)
I too learned this the hard way. I still haven't figured out why this is the case - like, is the inherent incidental irreducible complexity of human life too high, so it dominates majority of our actions?
Some of the rules are impossible to code generally enough, right? Like, "no defensive coding" - I can't imagine what kind of AST shenaningas you would have to do without basically banning `if`.
I mean, have you tried to ask it not to do those checks? It's similar to the OP about no defensive coding. In general, CC works better when you can tell it WHAT TO DO as opposed what NOT to do, but sometimes there is no way around it. What kind of checks it's adding? Like asserting that columns exist and stuff?