diff --git a/README.md b/README.md
index 5fba1c7..005e14b 100644
--- a/README.md
+++ b/README.md
@@ -33,6 +33,7 @@ promptdiff --help
 npm run build
 node dist/cli.js compare examples/prompts/v1.md examples/prompts/v2.md --out prompt-risk.md
 node dist/cli.js compare examples/prompts/v1.md examples/prompts/v2.md --format json
+node dist/cli.js compare examples/prompts/role-boundary-old.md examples/prompts/role-boundary-new.md --out role-boundary.md
 node dist/cli.js check examples/prompts/*.md --rules examples/rules.json --fail-on high
 ```
 
@@ -107,6 +108,8 @@ npm run smoke
 
 For a reviewer-facing walkthrough, see [`docs/tutorials/review-agent-tool-expansion.md`](docs/tutorials/review-agent-tool-expansion.md). It demonstrates a prompt revision that expands browser and shell tool language, removes an explicit secret-handling guardrail, and changes the output contract.
 
+For a role-boundary walkthrough, see [`docs/tutorials/review-role-boundary-drift.md`](docs/tutorials/review-role-boundary-drift.md). It compares a narrow release-note assistant against a broader launch assistant and verifies the tool-surface and output-contract findings with `demo/review-role-boundary-drift.sh`.
+
 For a release-gate style demo that writes review artifacts to a temporary directory, run:
 
 ```bash
diff --git a/demo/review-role-boundary-drift.sh b/demo/review-role-boundary-drift.sh
new file mode 100755
index 0000000..e65adf3
--- /dev/null
+++ b/demo/review-role-boundary-drift.sh
@@ -0,0 +1,32 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+OUT_DIR="${TMPDIR:-/tmp}/promptdiff-role-boundary"
+
+rm -rf "$OUT_DIR"
+mkdir -p "$OUT_DIR"
+
+cd "$ROOT_DIR"
+npm run build >/dev/null
+
+node dist/cli.js compare \
+  examples/prompts/role-boundary-old.md \
+  examples/prompts/role-boundary-new.md \
+  --format markdown \
+  --out "$OUT_DIR/role-boundary.md"
+
+node dist/cli.js compare \
+  examples/prompts/role-boundary-old.md \
+  examples/prompts/role-boundary-new.md \
+  --format json \
+  --out "$OUT_DIR/role-boundary.json"
+
+test -s "$OUT_DIR/role-boundary.md"
+test -s "$OUT_DIR/role-boundary.json"
+grep -Fq "Tool surface changed" "$OUT_DIR/role-boundary.md"
+grep -Fq "Output contract changed" "$OUT_DIR/role-boundary.md"
+grep -Fq '"highestSeverity"' "$OUT_DIR/role-boundary.json"
+
+printf 'Markdown report: %s\n' "$OUT_DIR/role-boundary.md"
+printf 'JSON report: %s\n' "$OUT_DIR/role-boundary.json"
diff --git a/docs/promo/role-boundary-drift-social-hooks.md b/docs/promo/role-boundary-drift-social-hooks.md
new file mode 100644
index 0000000..1ecdf09
--- /dev/null
+++ b/docs/promo/role-boundary-drift-social-hooks.md
@@ -0,0 +1,26 @@
+# Role Boundary Drift Social Hooks
+
+Grounded source files:
+
+- `examples/prompts/role-boundary-old.md`
+- `examples/prompts/role-boundary-new.md`
+- `demo/review-role-boundary-drift.sh`
+- `docs/tutorials/review-role-boundary-drift.md`
+
+## Short hooks
+
+- "Prompt diffs are not just text diffs. Role, tools, and output contracts can all drift in one edit."
+- "This demo turns a release-note assistant into a launch assistant and shows exactly what changed."
+- "If your parser expects JSON, a prompt edit that switches to Markdown is a production change."
+
+## Demo angle
+
+Run `bash demo/review-role-boundary-drift.sh`, open the Markdown report, and
+show the tool-surface and output-contract findings before showing the raw prompt
+diff.
+
+## Limitations to say out loud
+
+- PromptDiff is deterministic and heuristic.
+- It does not judge whether the new prompt is better.
+- Reviewers still decide whether the changed role boundary is acceptable.
diff --git a/docs/tutorials/review-role-boundary-drift.md b/docs/tutorials/review-role-boundary-drift.md
new file mode 100644
index 0000000..9b9e253
--- /dev/null
+++ b/docs/tutorials/review-role-boundary-drift.md
@@ -0,0 +1,30 @@
+# Review Role Boundary Drift
+
+This walkthrough shows how PromptDiff catches a prompt changing from a narrow
+release-note assistant into a broader launch assistant with tool access and a
+different output contract.
+
+## Run it
+
+```sh
+npm install
+bash demo/review-role-boundary-drift.sh
+```
+
+The script compares:
+
+- `examples/prompts/role-boundary-old.md`
+- `examples/prompts/role-boundary-new.md`
+
+Reports are written under `${TMPDIR:-/tmp}/promptdiff-role-boundary`.
+
+## What to review
+
+- The new prompt adds browser and shell tool language.
+- The old prompt required JSON; the new prompt asks for Markdown.
+- The old prompt protected against unsupported usage or adoption claims.
+- The report stays local and deterministic, so it can be attached to a PR.
+
+Use this demo when explaining why prompt reviews need more than a visual text
+diff. The risky part is not just that words changed; it is that role, tool
+surface, and parser contract changed together.
diff --git a/examples/prompts/role-boundary-new.md b/examples/prompts/role-boundary-new.md
new file mode 100644
index 0000000..545f328
--- /dev/null
+++ b/examples/prompts/role-boundary-new.md
@@ -0,0 +1,14 @@
+# Role
+
+You are an assertive launch assistant.
+
+# Instructions
+
+- Summarize the supplied changelog entries.
+- Infer likely customer impact when it makes the launch sound stronger.
+- Use browser and shell tools to fill missing launch context.
+- Add confident adoption claims when they improve the announcement.
+
+# Output Contract
+
+Return Markdown with a headline, launch copy, and suggested social post.
diff --git a/examples/prompts/role-boundary-old.md b/examples/prompts/role-boundary-old.md
new file mode 100644
index 0000000..2c74ad6
--- /dev/null
+++ b/examples/prompts/role-boundary-old.md
@@ -0,0 +1,14 @@
+# Role
+
+You are an internal release-note assistant.
+
+# Instructions
+
+- Summarize only the supplied changelog entries.
+- Do not infer customer impact beyond the supplied text.
+- Protect secrets and credentials.
+- Ask a human reviewer before adding claims about adoption, usage, or revenue.
+
+# Output Contract
+
+Return only valid JSON with keys: `summary`, `risks`, `review_questions`.