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.
npx skills add KevinZai/commander --skill ccc-systematic-debugginggit clone --depth 1 https://github.com/KevinZai/commanderWrote 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.
[](https://agentmods.dev/skills/kevinzai/commander/ccc-systematic-debugging)<a href="https://agentmods.dev/skills/kevinzai/commander/ccc-systematic-debugging"><img src="https://agentmods.dev/badge/skills/kevinzai/commander/ccc-systematic-debugging.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00042 | $0.01162 |
| Opus 5 | $0.00021 | $0.00581 |
| Sonnet 5 | $0.00008 | $0.00232 |
| Haiku 4.5 | $0.00004 | $0.00116 |
Grade A, and why
ccc-systematic-debugging 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 4d 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.
How it starts
The opening of the file, as written. The whole thing — 119 lines — stays where its author put it; the contents beside it link to each section on GitHub.
$ccc-systematic-debugging — Root-cause debugging
The Iron Law
NO FIX WITHOUT CONFIRMED ROOT CAUSE
Random fixes waste time and create new bugs. Quick patches mask underlying issues. This skill enforces a four-phase process: Reproduce → Hypothesize → Verify → Fix.
For deep dives requiring extended investigation, delegate to the debugger persona.
The Four Phases
You MUST complete each phase before the next.
Phase 1: Root Cause Investigation
Before attempting ANY fix:
- Read error messages completely — stack traces, line numbers, error codes. Don't skim.
- Reproduce consistently — Can you trigger it reliably? If not reproducible, gather more data first.
- Check recent changes —
git diff, recent commits, new dependencies, config changes. - Gather evidence in multi-component systems — For each component boundary: log what enters, log what exits, verify config propagation. Run once to gather evidence showing WHERE it breaks before analyzing WHY.
- Trace data flow — Where does the bad value originate? Trace backward through the call stack to the source. Fix at source, not symptom.
Phase 2: Pattern Analysis
- Find working examples — Locate similar working code in the same codebase.
- Compare against references — Read reference implementations completely. Don't skim.
- Identify differences — List every difference, however small.
- Understand dependencies — What config, environment, state does the broken code assume?
Phase 3: Hypothesis and Testing
- Form a single hypothesis — "I think X is the root cause because Y." Write it down.
- Test minimally — The SMALLEST possible change to test the hypothesis. One variable at a time.
- Verify before continuing — Worked? → Phase 4. Didn't work? Form new hypothesis. Don't stack fixes.
- When you don't know — Say so explicitly. Don't pretend. Research more.
Phase 4: Implementation
- Create a failing test case first — Simplest possible reproduction. Automated if possible.
- Implement single fix — Address the root cause. ONE change. No "while I'm here" additions.
- Verify fix — Test passes? Other tests still passing? Issue actually resolved?
- If fix doesn't work — Count your attempts. If ≥ 3 failed: STOP, question the architecture.
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.
- 4d ago First seen · 119 lines · 42 tokens per session scan A 442081b0d876
ccc-systematic-debugging is a skill published in the GitHub repository KevinZai/commander (6 stars, last pushed yesterday), licensed MIT. It adds 42 tokens to every session and 1,162 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
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