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 jabrena/plinth --skill 022-root-cause-analysisgit clone --depth 1 https://github.com/jabrena/plinthWrote 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/jabrena/plinth/022-root-cause-analysis)<a href="https://agentmods.dev/skills/jabrena/plinth/022-root-cause-analysis"><img src="https://agentmods.dev/badge/skills/jabrena/plinth/022-root-cause-analysis.svg" alt="Measured on agentmods" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00085 | $0.00808 |
| Opus 5 | $0.00043 | $0.00404 |
| Sonnet 5 | $0.00017 | $0.00162 |
| Haiku 4.5 | $0.00009 | $0.00081 |
Grade A, and why
022-root-cause-analysis 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 8d 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 — 72 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Root Cause Analysis
Guide the identification of root causes, not symptoms, for a framed problem, using Five Whys, Fishbone (Ishikawa), Current Reality Tree, and constraint identification. This is an interactive SKILL.
What is covered in this Skill?
- Five Whys for a linear causal chain from a symptom to a root cause
- Fishbone (Ishikawa) for categorized candidate causes across multiple dimensions
- Current Reality Tree for interconnected causes and effects with a small number of core problems
- Constraint identification for the limiting factor holding the current state in place
- Choosing the technique(s) proportionate to the problem's complexity
- Feeding root-cause findings into
023-assumption-analysisand the remaining Functional Specification lenses
Constraints
Distinguish root causes from symptoms before recommending a fix. When this technique is orchestrated by another workflow, the orchestrator owns clarifying-question sequencing; when applied standalone, ask directly.
- MUST read
references/022-root-cause-analysis.mdbefore applying Root Cause Analysis guidance - MUST distinguish a symptom (an observed effect) from a root cause (the condition that produces it)
- MUST apply Five Whys as a chain of "why" questions grounded in evidence from the problem frame, not assumption
- MUST apply Fishbone to organize candidate causes into categories (for example people, process, technology, environment) when more than one causal dimension is plausible
- MUST apply Current Reality Tree when multiple symptoms may share one or a small number of core problems connected by cause-effect relationships
- MUST identify the constraint limiting the current state, not only the most visible cause
- MUST NOT invent a root cause when the available evidence is vague or ambiguous; flag the gap for a clarifying question instead
When to use this skill
- Find the root cause of this problem
- Apply Five Whys to this issue
- Build a Fishbone diagram for this problem
- Use Current Reality Tree to connect these symptoms
- Identify the constraint limiting the current state
- Draft the Root Cause Analysis section of a Functional Specification
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 8d ago First seen · 72 lines · 85 tokens per session scan A 54a81f6bd163
022-root-cause-analysis is a skill published in the GitHub repository jabrena/plinth (436 stars, last pushed 3d ago), licensed Apache-2.0. It adds 85 tokens to every session and 808 once invoked, about $0.0004 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 2026-08-30.
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