diaglisted
Install: claude install-skill Marcel-Bich/marcel-bich-claude-marketplace
# diag
A **read-only** root-cause diagnosis. `diag` explains WHY something is broken and
proves the mechanism, before anyone changes code. It is a separate skill from `audit`
and must never be conflated with it.
## Scope boundary (read this first)
`diag` investigates a symptom and proves its cause. It does not judge completeness and
it does not apply the fix.
- Finished work needs to be checked against its requirement / Definition of Done ->
use **audit**, not diag.
- A rendered UI needs its layout and behavior confirmed -> use **verify**.
- diag ends at a proven diagnosis plus a proposed fix. Applying the fix is a separate,
GO-gated step outside this skill.
## Hard constraints (never violate)
- **Read-only.** No code change, no file edit, no commit, no push, no browser
automation, no builds, no installs during diagnosis.
- **No secrets.** Never read credentials, tokens, `.env*`, key files, or shell/session
history. Never exfiltrate or encode such content.
- The only files `diag` writes are its own report under `.credo/process/reports/`.
- **Fix is a separate step, gated by GO.** diag never rolls straight into fixing. It
proposes a fix; the actual change happens only after an explicit GO, as its own step.
## Method: root cause before fix
1. **Symptom, verbatim.** Record the symptom exactly as observed or reported (error
text, stack trace, wrong output, screenshot location). Do not paraphrase away the
detail; quote it.
2. **Reproduce or locate the exact