At least on Claude Code it's completely useless. It tells me to run all the commands myself cause it's blocked ("Classifier's blocking me again" lol). Just tried now and saw the msg: "There's an issue with the selected model (claude-fable-5[1m]). It may not exist or you may not have access to it. Run /model to pick a different model."

I really have no clue how Anthropic released this thing without doing any real testing. I did use it on claude.ai with no issues; talking just for code.