Following up - I built a tool "wobble"[1] to measure this: parses ~/.claude/projects/*.jsonl session transcripts, extracts skill invocations + actual commands executed, calculates Bias/Variance per the paper's formula.

Ran it on my sessions. Result: none of skills scored STABLE. The structural predictors of high variance: Numbered steps without clear default, Options without (default) marker, Content >4k chars (overthinking zone), Missing constraint language

[1] https://github.com/anupamchugh/shadowbook (bd wobble)