How do I install the Diff Skill skill?

Run npx skillmds@latest add serpro69/diff-skill in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Diff Skill safe to use?

This skill has not completed SkillMD's automated safety review yet. Capability flags: docs only. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Diff Skill?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Diff Skill free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Diff Skill?

serpro69 (@serpro69) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Diff Skill by serpro69 — Agent Skill

Name: Diff Skill
Rating: 4.2 (5 reviews)
Author: serpro69

Diff Skill

Compare two versions of a skill's instructions to detect degradations and complexity increases. TRIGGER when: user asks to diff, compare, or review changes to a skill's markdown instructions. Asymmetric check — only regressions count. Additions, clarifications, and strengthenings are not degradations. Compares HEAD → working tree by default. Walks the full reachable file set from SKILL.md via markdown links. Produces a report file under docs/reviews/diff-skill/ and an inline summary.

serpro69 Updated Sep 10, 2026

File contents

Diff Skill Instructions

Goal: Detect whether an edit to a skill's markdown instructions introduced degradations or made the skill harder for an LLM to follow.

Two judgment axes:

Degradation (asymmetric) — load-bearing instruction dropped, constraint weakened, verification step removed, scope narrowed, required output dropped, or reference broken. Content relocated but preserved is neutral.
Complexity — split into regressions (introduced or worsened by the edit, affects verdict) and pre-existing advisories (exist regardless of the edit, surfaced as improvement opportunities, does NOT affect verdict).

Conventions

Read capy knowledge base conventions at shared-capy-knowledge-protocol.md.

Required Outputs

Report written to docs/reviews/diff-skill/<slug>-<sha-a>-<sha-b>.md
Inline summary presented (under 10 lines: verdict, finding counts, report path)
Capy indexed under kk:review-findings if any degradation or complexity regression findings exist (skip on clean results and pre-existing advisories)

Invocation

$kk:diff-skill <skill-name>

Convenience shortcut: resolves klaude-plugin/skills/<skill-name>/SKILL.md. If not found, asks the user for the skill directory path.

Defaults: HEAD (before) → working tree (after). User can specify different refs in the prompt.

Workflow

Mandatory order — load instructions before acting on subject matter. The phases below are strictly sequential. Do not read skill content, build file sets, or produce judgments until you have loaded and internalized the full process file. The only early contact with the target skill is its name and SKILL.md path — enough to validate, not enough to judge.

See diff-process.md for the detailed step-by-step process.

---name: diff-skilldescription: Compare two versions of a skill's instructions to detect degradations and complexity increases. TRIGGER when: user asks to diff, compare, or review changes to a skill's markdown instructions. Asymmetric check — only regressions count. Additions, clarifications, and strengthenings are not degradations. Compares HEAD → working tree by default. Walks the full reachable file set from SKILL.md via markdown links. Produces a report file under docs/reviews/diff-skill/ and an inline summary.---# Diff Skill Instructions**Goal: Detect whether an edit to a skill's markdown instructions introduced degradations or made the skill harder for an LLM to follow.**Two judgment axes:1. **Degradation (asymmetric)** — load-bearing instruction dropped, constraint weakened, verification step removed, scope narrowed, required output dropped, or reference broken. Content relocated but preserved is neutral.2. **Complexity** — split into _regressions_ (introduced or worsened by the edit, affects verdict) and _pre-existing advisories_ (exist regardless of the edit, surfaced as improvement opportunities, does NOT affect verdict).## Conventions- **Read capy knowledge base conventions** at [shared-capy-knowledge-protocol.md](shared-capy-knowledge-protocol.md).## Required Outputs- [ ] Report written to `docs/reviews/diff-skill/<slug>-<sha-a>-<sha-b>.md`- [ ] Inline summary presented (under 10 lines: verdict, finding counts, report path)- [ ] Capy indexed under `kk:review-findings` if any degradation or complexity regression findings exist (skip on clean results and pre-existing advisories)## Invocation```$kk:diff-skill <skill-name>```Convenience shortcut: resolves `klaude-plugin/skills/<skill-name>/SKILL.md`. If not found, asks the user for the skill directory path.Defaults: `HEAD` (before) → working tree (after). User can specify different refs in the prompt.## Workflow**Mandatory order — load instructions before acting on subject matter.** The phases below are strictly sequential. Do not read skill content, build file sets, or produce judgments until you have loaded and internalized the full process file. The only early contact with the target skill is its name and SKILL.md path — enough to validate, not enough to judge.See [diff-process.md](diff-process.md) for the detailed step-by-step process.

Frequently asked questions