diff --git a/scripts/lib/validate-utils.mjs b/scripts/lib/validate-utils.mjs
index 8375b22f..9a55ac23 100644
--- a/scripts/lib/validate-utils.mjs
+++ b/scripts/lib/validate-utils.mjs
@@ -271,23 +271,32 @@ export function checkPublishableSourceUrl(errors, path, value) {
  * Push a "duplicate or missing id" error when `id` is falsy or already in
  * `seen`, then record `id` in `seen` regardless.
  *
- * validate-case-studies.mjs and validate-radar-reports.mjs each carried an
+ * validate-case-studies.mjs, validate-radar-reports.mjs,
+ * validate-metrics.mjs, and validate-launch-metrics.mjs each carried an
  * independent copy of this per-entry id-dedup check, byte-identical apart
- * from the `errors`/`ids` variable names.
+ * from the `errors`/`ids` variable names and the entry-type noun in the
+ * message.
  *
  * @param {Array<Object>} errors - Array to accumulate errors.
  * @param {string} path - File path or identifier used as the error's path.
  * @param {unknown} id - Candidate entry id (entry.id, not a display fallback).
  * @param {Set<unknown>} seen - Set of ids already encountered; mutated.
+ * @param {string} [message] - Error message; defaults to the generic form.
  * @returns {boolean} Whether `id` passed the check.
  */
-export function checkDuplicateOrMissingId(errors, path, id, seen) {
+export function checkDuplicateOrMissingId(
+  errors,
+  path,
+  id,
+  seen,
+  message = 'duplicate or missing id',
+) {
   const ok = Boolean(id) && !seen.has(id);
   if (!ok) {
     errors.push({
       path,
       severity: 'error',
-      message: 'duplicate or missing id',
+      message,
     });
   }
   seen.add(id);
diff --git a/scripts/validate-launch-metrics.mjs b/scripts/validate-launch-metrics.mjs
index a64d1418..be81ac47 100644
--- a/scripts/validate-launch-metrics.mjs
+++ b/scripts/validate-launch-metrics.mjs
@@ -1,6 +1,7 @@
 #!/usr/bin/env node
 import { readFileSync } from 'node:fs';
 import {
+  checkDuplicateOrMissingId,
   checkIsoTimestamp,
   checkUrl as checkUrlImpl,
   reportAndExit,
@@ -72,13 +73,13 @@ if (signals.length < 3 || signals.length > 5)
 const ids = new Set();
 for (const signal of signals) {
   const path = signal.id || '(missing id)';
-  if (!signal.id || ids.has(signal.id))
-    errors.push({
-      path,
-      severity: 'error',
-      message: 'duplicate or missing signal id',
-    });
-  ids.add(signal.id);
+  checkDuplicateOrMissingId(
+    errors,
+    path,
+    signal.id,
+    ids,
+    'duplicate or missing signal id',
+  );
   if (!signal.label)
     errors.push({ path, severity: 'error', message: 'missing label' });
   if (!signal.sourceUrl || !signal.collectedAt)
diff --git a/scripts/validate-metrics.mjs b/scripts/validate-metrics.mjs
index 92a2db36..f9ef039a 100644
--- a/scripts/validate-metrics.mjs
+++ b/scripts/validate-metrics.mjs
@@ -1,6 +1,7 @@
 #!/usr/bin/env node
 import { readFileSync } from 'node:fs';
 import {
+  checkDuplicateOrMissingId,
   checkIsoTimestamp,
   checkUrl as checkUrlImpl,
   reportAndExit,
@@ -69,13 +70,13 @@ checkUrl(
 );
 const ids = new Set();
 for (const metric of data.metrics || []) {
-  if (!metric.id || ids.has(metric.id))
-    errors.push({
-      path: metric.id,
-      severity: 'error',
-      message: 'duplicate or missing metric id',
-    });
-  ids.add(metric.id);
+  checkDuplicateOrMissingId(
+    errors,
+    metric.id,
+    metric.id,
+    ids,
+    'duplicate or missing metric id',
+  );
   if (
     metric.value === undefined ||
     metric.value === null ||
diff --git a/tests/validate-utils.test.mjs b/tests/validate-utils.test.mjs
index 8fd2a71c..819ca377 100644
--- a/tests/validate-utils.test.mjs
+++ b/tests/validate-utils.test.mjs
@@ -616,6 +616,25 @@ test('checkDuplicateOrMissingId reports a missing id and a repeat of one already
   }
 });
 
+test('checkDuplicateOrMissingId uses a caller-supplied message when given one', () => {
+  const errors = [];
+  const seen = new Set();
+  checkDuplicateOrMissingId(
+    errors,
+    'display-path',
+    undefined,
+    seen,
+    'duplicate or missing metric id',
+  );
+  assert.deepEqual(errors, [
+    {
+      path: 'display-path',
+      severity: 'error',
+      message: 'duplicate or missing metric id',
+    },
+  ]);
+});
+
 test('checkIsoTimestamp accepts a strict ISO 8601 UTC value and pushes no error', () => {
   const errors = [];
   const ok = checkIsoTimestamp(