diag SKILL.md skillB

diag from marcel-bich/marcel-bich-claude-marketplace is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

Install it, pinned
mdr add marcel-bich/marcel-bich-claude-marketplace/diag@git:20260704.cc8aebc

Pins git:20260704.cc8aebc in mdr.lock. Pin the fingerprint instead.

Audit grade
B, 16 of 17 checks passed
Kind
SKILL.md skill
Repository
marcel-bich/marcel-bich-claude-marketplace
Path
plugins/credo/skills/diag/SKILL.md
Versions recorded
1
Latest version
git:20260704.cc8aebc, committed Jul 4, 2026
Size
4,325 bytes
Repository stars
12
License
MIT

Read-only root-cause diagnosis for a symptom, bug, failure, or unexpected behavior. Establishes the mechanism at file:line and reads up the facts instead of guessing, before any fix is attempted. Produces a diagnosis report; the fix is always a separate step gated by an explicit GO. Use when something is broken, failing, throwing, or behaving unexpectedly and the cause is not yet proven, or when asked to investigate or find the root cause. Not for judging whether finished work meets its…

Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.

What the file says

# 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
…

Read the whole file at its exact version.

How to install

The exact contents, by fingerprint
mdr add marcel-bich/marcel-bich-claude-marketplace/diag@sha256:152568178fa09ae7

The line at the top of this page pins the label git:20260704.cc8aebc, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.

Badge

mdr badge

[![mdr](https://markdownregistry.com/badge/art_agputgbed3g3npmz.svg)](https://markdownregistry.com/a/art_agputgbed3g3npmz)

3 badge image fetches in 30 days. What the badge shows.

Versions

The registry has recorded 1 version of this file, committed on Jul 4, 2026.

versioncommittedcommitsizeaudit
git:20260704.cc8aebc latest2026-07-04 cc8aebc 4,325 BB view

Audit of the latest version

B  16 of 17 checks passed. Fixed automatic checks with no AI involved, so the same checks give the same answer every run.
  • fail: No instruction to read or print local credentials (matched: read credentials, tokens, `.env)
  • pass: Frontmatter block present
  • pass: Frontmatter declares a name
  • pass: Frontmatter declares a description
  • pass: Size between 200 bytes and 200 KB (4325 bytes)
  • pass: No zero-width or bidi control characters
  • pass: No instruction hidden inside an HTML comment
  • pass: No link to an exfiltration or paste host
  • pass: No credential-shaped string
  • pass: No instruction to send local credentials anywhere
  • pass: No text hidden with inline styles
  • pass: No prompt-injection phrasing
  • pass: No curl or wget piped into a shell
  • pass: No recursive delete of root, home or parent
  • pass: No base64 blob over 200 characters
  • pass: No link to a raw IP address
  • pass: No script tag

Starting a new one? Use a template for SKILL.md on mdpantry, which passes every one of these checks and says what to change in it.

Source

GitHub

marcel-bich/marcel-bich-claude-marketplace · 12 stars · license MIT · pushed 2026-11-03 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_agputgbed3g3npmz
GET https://markdownregistry.com/api/v1/resolve?ref=marcel-bich/marcel-bich-claude-marketplace/diag
GET https://markdownregistry.com/api/v1/blob/152568178fa09ae7cb3b19fbdf9700c42fb7b8e91c9a2507716a7995f4eaca54

Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.

Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.

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