Docs: RCA updates for Agent launch, segment scoping, PII guardrail

docs/root-cause-analysis.mdx

@@ -7,14 +7,14 @@
 
 Investigating anomalies or trends in your data is extremely manual. Teams spend hours each week running the same repetitive process (picking properties, running breakdowns, eyeballing segments) to figure out what drove a change in a metric.
 
-Mixpanel's **AI-Powered Root Cause Analysis (RCA)** feature does that work for you. Launch RCA from any Insights report or fired alert and an AI agent automatically diagnoses what changed: it validates the anomaly, runs the relevant breakdowns, ranks the dimensions that contributed most, and writes up an interpretation with a confidence level and suggested next steps — all delivered as a Board you and your team can keep working from.
+Mixpanel's **AI-Powered Root Cause Analysis (RCA)** feature does that work for you. Launch RCA from any Insights report, a fired alert, or the Mixpanel Agent and an AI agent automatically diagnoses what changed: it validates the anomaly, runs the relevant breakdowns, ranks the dimensions that contributed most, and writes up an interpretation with a confidence level and suggested next steps — all delivered as a Board you and your team can keep working from.
 
 ## How it works
 
 When you run an RCA, Mixpanel immediately launches a new Board and exposes the agent's reasoning as it works:
 
 1. **Validates the anomaly.** Confirms there's a real change to explain before going further, using a z-score to check the change is well outside normal day-to-day variation rather than routine noise or seasonality.
 2. **Selects properties to analyze.** An LLM agent picks which properties to break down on, combining properties Mixpanel suggests for the event with any you've prioritized in [Custom RCA Settings](#custom-rca-settings). It spreads picks across plausible cause categories (acquisition, audience, platform, data quality, user identity), filters out high-cardinality identifiers and near-duplicates, and factors in your project's business context.
 3. **Runs breakdowns.** Executes the chosen breakdowns to see which segments actually moved.
 4. **Writes an interpretation.** Fills the Board with contribution factor analysis (each segment's share of the total change), ranked dimensions, an AI-written explanation of the likely cause, a confidence level, and suggested next steps.
 
@@ -26,29 +26,38 @@
 
 <Step title="From an Insights report">
 
-Open any Insights chart, hover over a data point that looks unexpected, and choose **Root Cause Analysis** from the popover. RCA launches scoped to that event, segment, and time window.
+Open any Insights chart, hover over a data point that looks unexpected, and choose **Root Cause Analysis** from the popover. RCA launches scoped to that event and time window, and picks up any breakdown or segment already applied to the report so it analyzes the same slice you're looking at.
 </Step>
 
 <Step title="From a fired alert">
 
 When an alert fires, the notification (Slack, email, or webhook) includes a link that runs Root Cause Analysis and generates a Board for that alert. See [Alerts](/docs/features/alerts#root-cause-analysis) for how RCA fits into alerting.
 </Step>
+
+<Step title="From the Mixpanel Agent">
+
+Ask the [Mixpanel Agent](/docs/mixpanel-agent) to investigate a change (for example, _"explain this spike in signups"_) and it can kick off Root Cause Analysis for you. The analysis runs right in your Agent chat and produces the same RCA Board you can open and keep working from.
+</Step>
 </Steps>
 
 ## The RCA Board
 
 Because RCA generates a standard Mixpanel Board, it inherits all the capabilities of our typical Boards:
 
 - **Anyone in your project can open it.** RCA Boards are project-shared by default, so teammates can pick up the analysis where you left off.
 - **You can edit it like any Board.** Add cards, rearrange, annotate, or duplicate it if you want a private working copy.
 - **Cards include contribution factor analysis.** Each ranked dimension lands as its own card with the breakdown, contribution percentage, and supporting context. You can edit this as needed before sharing. 
 - **The interpretation card summarizes findings.** The AI's written explanation, confidence level, and suggested next steps live at the top of the Board so anyone scanning the results gets the punchline first.
 
+<Note>
+    RCA only surfaces data the person running it already has permission to see. It won't expose personal information (PII) that wouldn't otherwise be visible to that user.
+</Note>
+
 ## Custom RCA Settings
 
 Oftentimes, customers know which properties matter for their business and want to direct the root cause analysis to focus there first.
 
 In the AI Settings tab of your Project Settings, you can specify which event properties RCA should prioritize during analysis. For example, a marketing team that knows anomalies usually trace back to `utm_campaign_id` can point RCA at that dimension so it's always considered first. Properties you prioritize are combined with Mixpanel's automatic suggestions, so you never lose the agent's broader view — you just guide it toward the dimensions you care most about.
 
 <Info>
     These settings only influence which properties RCA prioritizes. They don't control RCA's analysis sequencing or methodology — regardless of the instructions you provide, the agent still validates the anomaly, runs its breakdowns, ranks contributing dimensions, and writes up its interpretation the same way.