diff --git a/incubator/@react-native-webapis/scan/README.md b/incubator/@react-native-webapis/scan/README.md
new file mode 100644
index 000000000..abcdd8ba2
--- /dev/null
+++ b/incubator/@react-native-webapis/scan/README.md
@@ -0,0 +1,31 @@
+# @react-native-webapis/scan
+
+[![Build](https://github.com/microsoft/rnx-kit/actions/workflows/build.yml/badge.svg)](https://github.com/microsoft/rnx-kit/actions/workflows/build.yml)
+[![npm version](https://img.shields.io/npm/v/@react-native-webapis/scan)](https://www.npmjs.com/package/@react-native-webapis/scan)
+
+`@react-native-webapis/scan` is a tool for scanning your code bases for
+potential uses of [Web APIs](https://developer.mozilla.org/en-US/docs/Web/API).
+
+## Build
+
+1. [Install Rust](https://www.rust-lang.org/learn/get-started)
+2. Build: `cargo build --release`
+
+A binary will be output at `target/release/scan`. Make not of this location, or
+copy the binary somewhere that you can easily access later.
+
+## Usage
+
+```sh
+./scan
+```
+
+This is currently a very simple tool. It takes no arguments and simply scans all
+`.js` and `.ts` files it finds in the current working directory. For each file
+it finds, it tries to parse using [SWC](https://swc.rs/). Once parsed, it will
+try to count all references to `navigator.*` and any identifiers listed in
+`src/web_apis.rs`. Files or directories that are listed in `src/ignored_dirs.rs`
+are skipped.
+
+You can see examples of output in `merge.mjs`. This is a script we use to
+aggregate the output from multiple repositories.
diff --git a/incubator/@react-native-webapis/scan/src/ignored_dirs.rs b/incubator/@react-native-webapis/scan/src/ignored_dirs.rs
index 390d4bc90..dba617f91 100644
--- a/incubator/@react-native-webapis/scan/src/ignored_dirs.rs
+++ b/incubator/@react-native-webapis/scan/src/ignored_dirs.rs
@@ -12,6 +12,7 @@ pub static IGNORED_DIRECTORIES: &'static [&str] = &[
     "@pnpm",
     "@react-native",
     "@react-native-community",
+    "@react-native-mac",
     "@react-native-webapis",
     "@react-native-windows",
     "@rnx-kit",
diff --git a/incubator/@react-native-webapis/scan/src/web_api_visitor.rs b/incubator/@react-native-webapis/scan/src/web_api_visitor.rs
index f42095a7a..cad3ae4cf 100644
--- a/incubator/@react-native-webapis/scan/src/web_api_visitor.rs
+++ b/incubator/@react-native-webapis/scan/src/web_api_visitor.rs
@@ -21,6 +21,7 @@ impl<'a> WebApiVisitor<'a> {
 }
 
 impl<'a> Visit for WebApiVisitor<'a> {
+    /// Count all references to `navigator.*`
     fn visit_member_expr(&mut self, member: &MemberExpr) {
         if let Expr::Ident(ident) = member.obj.as_ref() {
             if ident.as_ref() == "navigator" {
@@ -39,6 +40,7 @@ impl<'a> Visit for WebApiVisitor<'a> {
         }
     }
 
+    /// Count all uses of identifiers that found in `WEB_APIS`
     fn visit_new_expr(&mut self, expr: &NewExpr) {
         if let Expr::Ident(ident) = expr.callee.as_ref() {
             if let Ok(..) = WEB_APIS.binary_search(&ident.as_ref()) {