CoT works really well in qwen3.8-flash-next. I think a lot of the problems obversed are literal skill issue: dumping huge system prompts/skills that prime it over some broad scope, when the request is narrow.

The system prompt should be considered a starting point only if you want reusable intelligence and focus. It should not be a grab bag of tools and PR style guides, etc...

Grab your agent and inspect its prompt.