diff --git a/build/tasks/verify/verify-html-valid-for-vnu.mts b/build/tasks/verify/verify-html-valid-for-vnu.mts
index 7d2b49d70..ae248b50b 100644
--- a/build/tasks/verify/verify-html-valid-for-vnu.mts
+++ b/build/tasks/verify/verify-html-valid-for-vnu.mts
@@ -10,6 +10,14 @@ import vnu from 'vnu-jar';
 
 const htmlFiles = await glob(['_site/**.html', '!node_modules/']);
 
+// vnu responds to being given no files by printing its entire usage page and
+// exiting non-zero, which buries the actual problem: this task checks the
+// built site, and there is nothing built to check.
+if (htmlFiles.length === 0) {
+  console.error('No HTML under _site/ to check. Run `nps build` first.');
+  process.exit(1);
+}
+
 let exitCode = 0;
 const scripts = [`java -jar ${vnu} ${htmlFiles.join(' ')}`];
 
diff --git a/package-scripts.yml b/package-scripts.yml
index ead81be52..2f37c1de6 100644
--- a/package-scripts.yml
+++ b/package-scripts.yml
@@ -6,7 +6,10 @@ scripts:
     buildStyles: tsx build/tasks/compile/build-styles.mts
     siteifyHealthFiles: tsx build/tasks/compile/siteify-health-files.mts
   verify:
-    all: 'rc=0; for i in build/tasks/verify/*.mts; do tsx "$i" || rc=1; done; exit $rc'
+    # Announces each task and names the ones that failed. Without this the
+    # output is a wall of tool chatter with no indication of which of the
+    # thirteen produced it.
+    all: 'rc=0; failed=; for i in build/tasks/verify/*.mts; do echo "==> $i"; tsx "$i" || { rc=1; failed="$failed $i"; }; done; [ -z "$failed" ] || echo "FAILED:$failed" >&2; exit $rc'
     browserslist: tsx build/tasks/verify/verify-browserslist.mts
     scss: tsx build/tasks/verify/verify-scss.mts
     dockerfile: tsx build/tasks/verify/verify-dockerfile.mts