# Root Cause

> >

- **Type:** Skill
- **Install:** `agentstack add skill-lifedever-skills-plugin-root-cause`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [lifedever](https://agentstack.voostack.com/s/lifedever)
- **Installs:** 0
- **Category:** [Agent Skills](https://agentstack.voostack.com/c/agent-skills)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [lifedever](https://github.com/lifedever)
- **Source:** https://github.com/lifedever/skills-plugin/tree/main/skills/root-cause

## Install

```sh
agentstack add skill-lifedever-skills-plugin-root-cause
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# Root Cause — First-Principles Analysis

Force reasoning from fundamental facts. No analogies, no "this looks like X so do Y", no pattern-matching from similar codebases. Start from what is actually true and derive what should be done.

## When to Use

- **Debugging**: The surface fix is obvious, but you suspect a deeper issue
- **Architecture**: Deciding between approaches — is the familiar pattern actually right for this case?
- **Solution design**: Before adopting an existing pattern, verify it's the right one

## The Process

### Step 1: Strip Away Assumptions

List every assumption baked into the current approach or the proposed fix. For each one, ask: is this actually true in our specific context, or are we just carrying it over from convention?

Print each assumption as:

```
⚠️ Assumption: [what we're taking for granted]
   Evidence for: [does evidence support this?]
   Evidence against: [anything contradicting it?]
   Verdict: ✅ Holds / ❌ Doesn't hold / ❓ Unverified
```

### Step 2: Identify Fundamental Facts

List only what is provably true — from the code, the data, the logs, the runtime behavior. No "usually", no "typically", no "in most projects".

```
📌 Fact 1: [concrete observation with file:line or log evidence]
📌 Fact 2: [concrete observation with file:line or log evidence]
...
```

### Step 3: Derive the Answer from Facts

From the facts alone, reason forward:
- For bugs: what is the actual causal chain from trigger to symptom?
- For architecture: what does the data flow / responsibility boundary / actual constraint demand?
- For design: what solution follows from the real requirements, not from "how we did it last time"?

### Step 4: Compare with the Obvious Answer

Now compare your first-principles derivation with whatever the "obvious" or "conventional" answer was:

```
🔍 Conventional approach: [what pattern-matching would suggest]
🔍 First-principles answer: [what the facts demand]
🔍 Delta: [where they differ and why it matters]
```

If they agree — great, the conventional approach is validated. If they diverge — the delta is where the real insight lives.

### Step 5: Recommend

State the recommendation clearly. If it differs from the obvious approach, explain why the first-principles answer is better with specific evidence, not just "it's more correct".

## Hard Rules

1. **No "usually" / "typically" / "in most cases"** — these are analogies in disguise. State what is true HERE.
2. **No solution before diagnosis** — if this is a bug, you must trace the actual causal chain before proposing a fix.
3. **Challenge your own answer** — after deriving the answer, spend 30 seconds trying to break it. If you find a flaw, iterate.
4. **Cite evidence** — every claim must reference a file:line, a log entry, a data point, or a reproducible observation. "I believe" is not evidence.

## Examples of First-Principles Thinking

| Surface answer | First-principles question | What you might find |
|---|---|---|
| "The API is slow, add a cache" | Why is it slow? What's the actual bottleneck? | The N+1 query is the real problem; a cache just hides it |
| "Add a retry for this flaky test" | Why does it flake? What's the timing dependency? | A race condition in setup that retry can't fix |
| "Use the same pattern as module X" | Does this module have the same constraints as X? | X was designed for batch processing; this is real-time — different pattern needed |
| "The config was changed, revert it" | Why was the config changed? What was the original intent? | The config change exposed a deeper routing issue that existed for months |

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [lifedever](https://github.com/lifedever)
- **Source:** [lifedever/skills-plugin](https://github.com/lifedever/skills-plugin)
- **License:** MIT

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-lifedever-skills-plugin-root-cause
- Seller: https://agentstack.voostack.com/s/lifedever
- Browse the marketplace: https://agentstack.voostack.com/browse

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Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.