# Root Cause Investigation Playbook

Companion to **AI Agents for eCommerce Root Cause Analysis**.

Question: **Why did revenue decline last week?** This is **not** “summarize the dashboard.” Every hop needs a tool. Correlation is not causation. A human signs the narrative.

```text
Revenue → Traffic → Conversion → Products → Inventory → Marketing → Customer behavior
```

## Hop contract

| Hop | Tool (name yours) | Allowed claim | Forbidden claim |
| --- | ----------------- | ------------- | --------------- |
| Revenue | `salesByPeriod` | Revenue down X vs prior week **as measured** | “Because of the brand” |
| Traffic | `sessionsByChannel` | Sessions down on channel Y | “Google hates us” |
| Conversion | `conversionFunnel` | Step Z dropped | “Checkout UX is broken” without a funnel tool |
| Products | `salesBySku` | SKU mix shifted | “Quality got worse” without reviews tool |
| Inventory | `getInventory` | Advertised SKU ATP = 0 `asOf` | Stockout caused conversion without join |
| Marketing | `adSpendByCampaign` | Spend down on campaign C | ROAS story without attribution tool |
| Behavior | `repeatPurchaseRate` | Repeat rate moved | “Customers are angry” |

If a hop has **no tool**, the agent stops and lists the gap. It does not fill the gap with language.

## Output

```json
{
  "question": "Why did revenue decline last week?",
  "period": "demo-week",
  "contributors": [
    {
      "claim": "ATP was 0 on advertised SKU DEMO-1 from Tue 14:00",
      "evidence_tool": "getInventory",
      "evidence_ref": "sku:DEMO-1",
      "confidence": "measured",
      "causation": "possible_contributor"
    }
  ],
  "unknowns": ["checkout step drop — no funnel tool"],
  "human_validation": "required"
}
```

Baymard **70.22%** average cart abandonment is **industry context**, not your diagnosis.

## Related

- Daily brief (not RCA): [`operations-daily-brief-schema.md`](operations-daily-brief-schema.md)
- Analytics tools: [`analytics-tool-catalog.md`](analytics-tool-catalog.md)
- Alerts: [`evidence-based-alert-schema.md`](evidence-based-alert-schema.md)