diff --git a/.github/scripts/pr-labeler.js b/.github/scripts/pr-labeler.js
index 25aa62950..bda2757c0 100644
--- a/.github/scripts/pr-labeler.js
+++ b/.github/scripts/pr-labeler.js
@@ -52,10 +52,15 @@ function isDocumentationFile(path) {
     /^README(?:_[A-Z]+)?\.md$/.test(path) ||
     /^(CONTRIBUTING|SECURITY)\.md$/.test(path) ||
     /^docs\//.test(path) ||
+    /^[^/]+\/agent-harness\/.*\.md$/i.test(path) ||
     /^[^/]+\.md$/i.test(path)
   );
 }
 
+function isHarnessImplementationFile(path) {
+  return isHarnessFile(path) && !isDocumentationFile(path);
+}
+
 function titleLooksLikeRegistryCli(title) {
   return /\b(add|introduce|new)\b/i.test(title) && /\b(cli|harness|registry)\b/i.test(title);
 }
@@ -64,7 +69,7 @@ function computeScriptLabels(files, title) {
   const paths = files.map((file) => file.filename);
   const labelsToApply = new Set();
 
-  const hasHarnessChange = paths.some(isHarnessFile);
+  const hasHarnessImplementationChange = paths.some(isHarnessImplementationFile);
   const hasNewHarness = files.some(isNewHarnessManifest);
   const registryOnly = paths.length > 0 && paths.every((path) => REGISTRY_FILES.has(path));
   const registryNewCli = registryOnly && titleLooksLikeRegistryCli(title || "");
@@ -72,7 +77,7 @@ function computeScriptLabels(files, title) {
 
   if (hasNewHarness || registryNewCli) {
     labelsToApply.add("new-cli");
-  } else if (hasHarnessChange) {
+  } else if (hasHarnessImplementationChange) {
     labelsToApply.add("existing-cli-fix");
   }
 
diff --git a/.github/scripts/tests/pr-labeler.test.js b/.github/scripts/tests/pr-labeler.test.js
index 887e7d863..6c48a4b21 100644
--- a/.github/scripts/tests/pr-labeler.test.js
+++ b/.github/scripts/tests/pr-labeler.test.js
@@ -197,3 +197,12 @@ test("mixed README and harness changes are not documentation-only", () => {
 
   assert.deepStrictEqual(labels, ["existing-cli-fix"]);
 });
+
+test("harness README-only changes are documentation", () => {
+  const labels = computeAllLabels({
+    title: "docs(firefly-iii): clarify setup notes",
+    files: [{filename: "firefly-iii/agent-harness/README.md", status: "modified"}],
+  });
+
+  assert.deepStrictEqual(labels, ["documentation"]);
+});