rules-distill

rules-distill is a skill for Claude Code, Codex from JunMystery/Agent-Guidance-Python. It costs 28 tokens per session (2,245 once invoked), scanned A, a copy of rules-distill, MIT.

A process for scanning installed skills and turning repeated principles into reusable rule files. It combines automatic collection of skill and rule information with cross-reading and human-style judgment.

In plain words
What is it for?
Use it during periodic rules maintenance or after a skill review to append, revise, or create rule files based on shared principles.
Why use it?
It helps keep project rules aligned with the guidance already present in installed skills and makes recurring practices easier to apply consistently.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: reads .claude/ paths; mentions subagents.

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/junmystery/agent-guidance-python/rules-distill
Any agent
npx skills add JunMystery/Agent-Guidance-Python --skill rules-distill
Clone the repo
git clone --depth 1 https://github.com/JunMystery/Agent-Guidance-Python

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for rules-distill

README.md
[![agentmods](https://agentmods.dev/badge/skills/junmystery/agent-guidance-python/rules-distill.svg)](https://agentmods.dev/skills/junmystery/agent-guidance-python/rules-distill)
Your own site
<a href="https://agentmods.dev/skills/junmystery/agent-guidance-python/rules-distill"><img src="https://agentmods.dev/badge/skills/junmystery/agent-guidance-python/rules-distill.svg" alt="Measured on agentmods" height="20"></a>
Per session 28 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,245 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 94% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00028 $0.02245
Opus 5 $0.00014 $0.01123
Sonnet 5 $0.00006 $0.00449
Haiku 4.5 $0.00003 $0.00225

Measured 2d ago against content hash 5c457a1789f7, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

rules-distill scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

94% identical to rules-distill — 9 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/rules-distill/SKILL.md · 265 lines

How it starts

The opening of the file, as written. The whole thing — 265 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Rules Distill

Scan installed skills, extract cross-cutting principles that appear in multiple skills, and distill them into rules — appending to existing rule files, revising outdated content, or creating new rule files.

Applies the "deterministic collection + LLM judgment" principle: scripts collect facts exhaustively, then an LLM cross-reads the full context and produces verdicts.

When to Use

  • Periodic rules maintenance (monthly or after installing new skills)
  • After a skill-stocktake reveals patterns that should be rules
  • When rules feel incomplete relative to the skills being used

How It Works

The rules distillation process follows three phases:

Phase 1: Inventory (Deterministic Collection)

1a. Collect skill inventory
bash ~/.claude/skills/rules-distill/scripts/scan-skills.sh
1b. Collect rules index
bash ~/.claude/skills/rules-distill/scripts/scan-rules.sh
1c. Present to user
Rules Distillation — Phase 1: Inventory
────────────────────────────────────────
Skills: {N} files scanned
Rules:  {M} files ({K} headings indexed)

Proceeding to cross-read analysis...

Phase 2: Cross-read, Match & Verdict (LLM Judgment)

Extraction and matching are unified in a single pass. Rules files are small enough (~800 lines total) that the full text can be provided to the LLM — no grep pre-filtering needed.

Batching

Group skills into thematic clusters based on their descriptions. Analyze each cluster in a subagent with the full rules text.

Cross-batch Merge

After all batches complete, merge candidates across batches:

  • Deduplicate candidates with the same or overlapping principles
  • Re-check the "2+ skills" requirement using evidence from all batches combined — a principle found in 1 skill per batch but 2+ skills total is valid
Subagent Prompt

Launch a general-purpose Agent with the following prompt:

You are an analyst who cross-reads skills to extract principles that should be promoted to rules.

## Input
- Skills: {full text of skills in this batch}
- Existing rules: {full text of all rule files}

## Extraction Criteria

Include a candidate ONLY if ALL of these are true:

1. **Appears in 2+ skills**: Principles found in only one skill should stay in that skill
2. **Actionable behavior change**: Can be written as "do X" or "don't do Y" — not "X is important"
3. **Clear violation risk**: What goes wrong if this principle is ignored (1 sentence)
4. **Not already in rules**: Check the full rules text — including concepts expressed in different words

## Matching & Verdict

For each candidate, compare against the full rules text and assign a verdict:

- **Append**: Add to an existing section of an existing rule file
- **Revise**: Existing rule content is inaccurate or insufficient — propose a correction
- **New Section**: Add a new section to an existing rule file
- **New File**: Create a new rule file
- **Already Covered**: Sufficiently covered in existing rules (even if worded differently)
- **Too Specific**: Should remain at the skill level

## Output Format (per candidate)

```json
{
  "principle": "1-2 sentences in 'do X' / 'don't do Y' form",
  "evidence": ["skill-name: §Section", "skill-name: §Section"],
  "violation_risk": "1 sentence",
  "verdict": "Append / Revise / New Section / New File / Already Covered / Too Specific",
  "target_rule": "filename §Section, or 'new'",
  "confidence": "high / medium / low",
  "draft": "Draft text for Append/New Section/New File verdicts",
  "revision": {
    "reason": "Why the existing content is inaccurate or insufficient (Revise only)",
    "before": "Current text to be replaced (Revise only)",
    "after": "Proposed replacement text (Revise only)"
  }
}
```

## Exclude

- Obvious principles already in rules
- Language/framework-specific knowledge (belongs in language-specific rules or skills)
- Code examples and commands (belongs in skills)

Read the full file on GitHub · 265 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 265 lines · 28 tokens per session scan A 5c457a1789f7

Subscribe to this mod's changes

rules-distill is a skill published in the GitHub repository JunMystery/Agent-Guidance-Python (2 stars, last pushed 1mo ago), licensed MIT. It adds 28 tokens to every session and 2,245 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. It is 94% identical to rules-distill, differing in 9 lines, and is treated as a copy.

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