Not the person you're asking, but I did that by explaining to Fable my problem with Opus's gobbledygook and having it write a Claude skill for producing clear explanations in its reports to me. I also had it add notes about the need for clearer writing to CLAUDE.md and other project documentation. Opus's subsequent reports to me have been much clearer.

Here’s an example of one of those Claude skills, in a public repository I manage:

https://github.com/tkgally/je-dict-1/blob/main/.claude/skill...

Fable wrote it specifically for this project.

And then both Opus and Fable will happily ignore these random markdown files (happens to me all the time)