diff --git a/.evidence/readme-after.png b/.evidence/readme-after.png
new file mode 100644
index 0000000..c108f6c
Binary files /dev/null and b/.evidence/readme-after.png differ
diff --git a/.evidence/readme-before.png b/.evidence/readme-before.png
new file mode 100644
index 0000000..bd92474
Binary files /dev/null and b/.evidence/readme-before.png differ
diff --git a/README.md b/README.md
index c92a50f..55137e6 100644
--- a/README.md
+++ b/README.md
@@ -9,5 +9,5 @@ npm run dev
 
 ## Notes
 
-- [App.svelte](https://github.com/fastrepl/contextlengthof/blob/main/src/App.svelte) is all you need to edit.
+- [App.svelte](https://github.com/fastrepl/contextlengthof/blob/main/src/App.svelte) contains the main app code.
 - [PicoCSS](https://picocss.com/) is used for styling.
diff --git a/scripts/verify-readme.py b/scripts/verify-readme.py
new file mode 100644
index 0000000..fb8cf8b
--- /dev/null
+++ b/scripts/verify-readme.py
@@ -0,0 +1,20 @@
+from pathlib import Path
+
+
+readme = Path(__file__).resolve().parents[1] / "README.md"
+content = readme.read_text()
+
+expected = (
+    "[App.svelte](https://github.com/fastrepl/contextlengthof/blob/main/src/App.svelte) "
+    "contains the main app code."
+)
+
+if expected not in content:
+    raise SystemExit(
+        "README should describe App.svelte as containing the main app code."
+    )
+
+if "is all you need to edit" in content:
+    raise SystemExit("README should not imply App.svelte is always the only file to edit.")
+
+print("PASS: README clearly describes App.svelte.")