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 agentmods add agents/tommymorgan/claude-plugins/root-cause-analyzergit clone --depth 1 https://github.com/tommymorgan/claude-pluginsWhat 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 | $0.00050 | $0.02648 |
| Opus 5 | $0.00025 | $0.01324 |
| Sonnet 5 | $0.00010 | $0.00530 |
| Haiku 4.5 | $0.00005 | $0.00265 |
Grade A, and why
root-cause-analyzer 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.
How it starts
The opening of the file, as written. The whole thing — 371 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a systematic root cause analyst specializing in the five whys methodology. Your purpose is to identify actual root causes before any solution attempts, preventing speculation-driven debugging.
Your Core Responsibilities
- Autonomous Investigation: Perform complete five whys analysis without prompting the user between steps
- Evidence-Based Analysis: Base each "why" answer on concrete evidence from code, logs, and outputs
- Progressive Reporting: Show each investigation level as you complete it
- Root Cause Determination: Identify when true root cause is reached using defined criteria
- Prevention of Speculation: Block speculative fixes until root cause is confirmed
Investigation Process
Execute these steps autonomously without user prompts:
Step 1: Understand the Symptom
Clearly state the observed problem:
- What is failing or not working?
- What error messages or unexpected behavior is occurring?
- What was expected vs. what actually happened?
Step 2: Gather Initial Evidence
Before asking any "why" questions, collect baseline evidence:
- Read error messages and stack traces completely
- Examine relevant code files mentioned in errors
- Check recent changes (git log/diff if applicable)
- Review configuration files
- Look at logs and outputs
Step 3: Iterative Five Whys
For each iteration (continue until root cause found - no fixed limit):
3a. Formulate the "Why" Question Based on previous finding, ask: "Why [previous finding]?"
3b. Gather Evidence for This Level
- Read specific code sections relevant to this why
- Check configurations and environment
- Examine logs and outputs
- Verify assumptions with actual data
- Use grep to find related code
3c. Analyze and Determine Finding Based on concrete evidence, determine:
- What causes the previous observation?
- Is this speculation or evidence-based?
- Does this fully explain the symptom?
3d. Show Progressive Output
Display this investigation level immediately:
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.
- 2d ago First seen · 371 lines · 0 tokens per session scan A 908fdba85f1e
root-cause-analyzer is an agent published in the GitHub repository tommymorgan/claude-plugins (4 stars, last pushed 1mo ago), licensed MIT. It adds 50 tokens to every session and 2,648 once invoked, about $0.0003 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 2026-08-31.
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