rubber-duck SKILL.md skillA
rubber-duck from jim60105/copilot-prompt is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add jim60105/copilot-prompt/rubber-duck@git:20260525.d5d181cPins git:20260525.d5d181c in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- jim60105/copilot-prompt
- Path
skills/rubber-duck/SKILL.md- Versions recorded
- 3
- Latest version
- git:20260525.d5d181c, committed May 25, 2026
- First version recorded
- May 19, 2026
- Size
- 6,153 bytes
- Repository stars
- 22
- License
- GFDL-1.3
Invoke a Rubber Duck Reviewer subagent to independently critique plans and implementations before proceeding. Use when the agent is about to implement a non-trivial plan (multi-file changes, architectural decisions, security-sensitive logic, database schema changes), after completing a self-contained unit of work (module, endpoint, feature), when stuck or facing repeated failures (same test fails 2+ times, unexpected results), or when the agent wants independent validation of assumptions and…
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
# Rubber Duck Reviewer Invoke a separate, stateless subagent to independently critique your plan or implementation before proceeding. This catches blind spots, logic errors, and security issues while course corrections are still cheap. **Most non-trivial tasks that fail had issues a rubber-duck critique could have caught early.** Treat this as a required step for non-trivial work, not an optional enhancement. ## When to Invoke **Always invoke before implementing** when: - Plan touches more than one file - Plan involves database schema changes, API contracts, or security-sensitive logic - Making an architectural decision with long-term consequences - Uncertain about an assumption **Invoke after completing a unit of work** when: - Finished implementing a module, endpoint, or feature - Wrote tests and want to validate coverage of critical paths - Refactored non-trivially **Invoke reactively** when: - Same test fails after 2+ fix attempts - An approach produces unexpected results - Your mental model of the system may be wrong **Do NOT invoke** when: - Single-file edit with no side effects - Purely cosmetic change (docs, renaming, formatting) …
Read the whole file at its exact version.
How to install
mdr add jim60105/copilot-prompt/rubber-duck@sha256:e55f4a6616563419The line at the top of this page pins the label git:20260525.d5d181c, 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.
[](https://markdownregistry.com/a/art_dr3lluonb3tfiznh)
5 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 3 versions of this file, between May 19, 2026 and May 25, 2026, about one every 3 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260525.d5d181c latest | 2026-05-25 | d5d181c | 6,153 B | A | view · diff |
| git:20260525.c389ab4 | 2026-05-25 | c389ab4 | 6,120 B | A | view · diff |
| git:20260519.141683d | 2026-05-19 | 141683d | 6,093 B | A | view |
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (6153 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 instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
jim60105/copilot-prompt · 22 stars · license GFDL-1.3 · pushed 2026-10-16 · branch master
API
GET https://markdownregistry.com/api/v1/artifacts/art_dr3lluonb3tfiznh GET https://markdownregistry.com/api/v1/resolve?ref=jim60105/copilot-prompt/rubber-duck GET https://markdownregistry.com/api/v1/blob/e55f4a661656341930002aa6a0ff6df75098b14bd0911793bf04efc930072491
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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