diff --git a/.github/workflows/schema-sync.yml b/.github/workflows/schema-sync.yml
index e0af002..70497e5 100644
--- a/.github/workflows/schema-sync.yml
+++ b/.github/workflows/schema-sync.yml
@@ -76,3 +76,13 @@ jobs:
               --label schema-sync \
               --label "automated pr"
           fi
+
+          # Keep a coverage comment on the PR, updated on each sync
+          npm run --silent schema:coverage > coverage.md
+          if [ ! -s coverage.md ]; then
+            printf '## Docs coverage\n\nPolicy docs and schema entries match.\n' > coverage.md
+          fi
+          gh pr comment automation/schema-sync \
+            --body-file coverage.md \
+            --edit-last \
+            --create-if-none
diff --git a/package.json b/package.json
index d747f4f..582168a 100644
--- a/package.json
+++ b/package.json
@@ -9,6 +9,7 @@
     "preview": "astro preview",
     "astro": "astro",
     "schema:sync": "node scripts/sync-schema.mjs",
+    "schema:coverage": "node scripts/check-schema-coverage.mjs",
     "release-dates:sync": "node scripts/sync-release-dates.mjs"
   },
   "dependencies": {
diff --git a/scripts/check-schema-coverage.mjs b/scripts/check-schema-coverage.mjs
new file mode 100644
index 0000000..d85d7c6
--- /dev/null
+++ b/scripts/check-schema-coverage.mjs
@@ -0,0 +1,45 @@
+#!/usr/bin/env node
+// Compare policies in schema/policies-schema.json against policy docs pages
+// and print as markdown. Used by .github/workflows/schema-sync.yml
+import { readFile, readdir } from "node:fs/promises";
+import { fileURLToPath } from "node:url";
+import { dirname, resolve, join, parse } from "node:path";
+
+const REPO_ROOT = resolve(dirname(fileURLToPath(import.meta.url)), "..");
+const SCHEMA_PATH = join(REPO_ROOT, "schema", "policies-schema.json");
+const DOCS_DIR = join(REPO_ROOT, "src", "content", "docs", "reference", "policies");
+const DOCS_PATH = "src/content/docs/reference/policies";
+
+// Docs pages that intentionally have no schema entry.
+const NOT_IN_SCHEMA = new Set([
+  // macOS plist-only switch, read before policies.json is parsed.
+  "EnterprisePoliciesEnabled",
+]);
+
+const schema = JSON.parse(await readFile(SCHEMA_PATH, "utf8"));
+const schemaPolicies = new Set(Object.keys(schema.properties ?? {}));
+
+const docPages = new Set(
+  (await readdir(DOCS_DIR)).filter((f) => /\.mdx?$/.test(f)).map((f) => parse(f).name),
+);
+
+const missingDocs = [...schemaPolicies].filter((p) => !docPages.has(p)).sort();
+const missingSchema = [...docPages]
+  .filter((p) => !schemaPolicies.has(p) && !NOT_IN_SCHEMA.has(p))
+  .sort();
+
+// Print nothing when docs and schema match
+if (missingDocs.length === 0 && missingSchema.length === 0) process.exit(0);
+
+const lines = ["## Docs coverage", ""];
+
+if (missingDocs.length > 0) {
+  lines.push(`**Policies without docs** (add a page under \`${DOCS_PATH}/\`):`, "");
+  lines.push(...missingDocs.map((p) => `- \`${p}\``), "");
+}
+if (missingSchema.length > 0) {
+  lines.push("**Docs without a schema entry** (removed or renamed upstream?):", "");
+  lines.push(...missingSchema.map((p) => `- \`${p}\``), "");
+}
+
+console.log(lines.join("\n").trimEnd());