053-design-simple-rules SKILL.md skillA
053-design-simple-rules from jabrena/plinth is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add jabrena/plinth/053-design-simple-rules@v0.19.0Pins v0.19.0 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- jabrena/plinth
- Path
skills/053-design-simple-rules/SKILL.md- Versions recorded
- 3
- Latest version
- v0.19.0, committed Sep 26, 2026
- First version recorded
- Jul 10, 2026
- Size
- 3,389 bytes
- Repository stars
- 461
- License
- Apache-2.0
Use when Java design, refactoring, or implementation tradeoffs should be evaluated with Kent Beck's simple design rules, including passes the tests, reveals intention, has no duplication, and has the fewest elements. This should trigger for requests such as Apply simple design rules; Review this design with Beck's rules; Choose between these refactoring options; Keep this Java design simple. Part of Plinth Toolkit.
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
# Simple Design Rules Guide Java developers through Kent Beck's simple design rules when evaluating design and refactoring choices. **This is an interactive SKILL**. **What is covered in this Skill?** - Using tests as the first correctness boundary before design cleanup - Revealing intention and maximizing clarity before abstraction pressure - Reducing duplication without hiding domain meaning or worsening readability - Treating fewer elements as the final simplification pressure after correctness, clarity, and duplication - Comparing Java design and refactoring options with the ordered rules - Reporting the chosen option, tradeoffs, validation signal, and remaining risk ## Constraints Apply simple design rules in priority order, and do not optimize later rules by weakening earlier rules. - **MUST** read `references/053-design-simple-rules.md` before applying the rules - **MUST** evaluate the rules in this order: passes the tests, reveals intention, has no duplication, has the fewest elements - **MUST** treat passing tests as the correctness boundary before design cleanup - **MUST** prefer clear intention over abstraction for its own sake …
Read the whole file at its exact version.
How to install
mdr add jabrena/plinth/053-design-simple-rules@sha256:56353e85cd224f9bThe line at the top of this page pins the label v0.19.0, 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_p53vzlbxadvbr6m5)
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Versions
The registry has recorded 3 versions of this file, between Jul 10, 2026 and Sep 26, 2026, about one every 39 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| v0.19.0 latest | 2026-09-26 | 9569c35 | 3,389 B | A | view · diff |
| v0.18.0 | 2026-08-01 | 26b0e71 | 3,389 B | A | view · diff |
| v0.17.0 | 2026-07-10 | aaee915 | 3,389 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 (3389 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
jabrena/plinth · 461 stars · license Apache-2.0 · pushed 2026-11-06 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_p53vzlbxadvbr6m5 GET https://markdownregistry.com/api/v1/resolve?ref=jabrena/plinth/053-design-simple-rules GET https://markdownregistry.com/api/v1/blob/56353e85cd224f9b7bad251050f3ffe17b8dc8638441ffed67fc4932a7cf444a
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.