diff --git a/examples/app-showcase/src/ui/reports/index.ts b/examples/app-showcase/src/ui/reports/index.ts
index 1054fbd9a08..28b7ce4486c 100644
--- a/examples/app-showcase/src/ui/reports/index.ts
+++ b/examples/app-showcase/src/ui/reports/index.ts
@@ -26,7 +26,7 @@ export const HoursByStatusReport = defineReport({
 export const StatusPriorityMatrixReport = defineReport({
   name: 'showcase_status_priority_matrix',
   label: 'Status × Priority (Matrix)',
-  description: 'Task counts cross-tabulated by status and priority.',
+  description: 'Estimated hours cross-tabulated by status and priority.',
   type: 'matrix',
   drilldown: true,
   // ADR-0021 D2 — true pivot: `rows` down × `columns` across, measures in cells.
diff --git a/examples/app-showcase/test/report-description-measure.test.ts b/examples/app-showcase/test/report-description-measure.test.ts
new file mode 100644
index 00000000000..7352273e8ec
--- /dev/null
+++ b/examples/app-showcase/test/report-description-measure.test.ts
@@ -0,0 +1,84 @@
+// Copyright (c) 2025 ObjectStack. Licensed under the Apache-2.0 license.
+
+import { describe, it, expect } from 'vitest';
+
+import * as datasets from '../src/ui/datasets/index.js';
+import { allReports } from '../src/ui/reports/index.js';
+
+/**
+ * A report's `description` is the subtitle the console renders under its
+ * title; its cells are the measures `values` binds. The two must name the same
+ * quantity. The Status × Priority matrix shipped "Task counts cross-tabulated
+ * by status and priority." over `values: ['est_hours']` — a `sum` of
+ * `estimate_hours` — so a reader trusting the subtitle took a cell reading
+ * 60.0 for sixty tasks when it held one task's estimated hours (#23931).
+ *
+ * Graded against the bound DATASET's own declarations, never against a copy of
+ * the subtitle text:
+ *
+ * - a bound measure is named by its declared `label` — the name the cell's
+ *   header shows — and a `count` measure may also be named in count words;
+ * - the converse is the defect as shipped: count words in a subtitle whose
+ *   bound measures count nothing.
+ *
+ * Joined reports bind their measures per block and carry no top-level
+ * `values`, so their subtitle names no single quantity; they are out of scope
+ * by construction, not by a skip.
+ */
+
+type Measure = { name: string; label?: unknown; aggregate?: string };
+
+const MEASURES_BY_DATASET = new Map<string, readonly Measure[]>(
+  Object.values(datasets).map((d) => [d.name, d.measures as readonly Measure[]]),
+);
+
+/** The words a subtitle uses to say its cells are counts. */
+const COUNT_WORDS = /\b(counts?|number of)\b/i;
+
+/** The plain-string copy this pin knows how to read; an inline locale map is reported, not guessed. */
+function plain(value: unknown, what: string): string {
+  expect(typeof value, `${what} must be a plain string for this pin to read it`).toBe('string');
+  return value as string;
+}
+
+function boundMeasures(report: (typeof allReports)[number]): Measure[] {
+  const measures = MEASURES_BY_DATASET.get(report.dataset ?? '');
+  expect(measures, `${report.name}: dataset '${report.dataset}' is not a showcase dataset`).toBeDefined();
+  return (report.values ?? []).map((name) => {
+    const measure = measures!.find((m) => m.name === name);
+    expect(measure, `${report.name}: measure '${name}' is not declared on '${report.dataset}'`).toBeDefined();
+    return measure!;
+  });
+}
+
+const graded = allReports
+  .filter((r) => r.description !== undefined && (r.values?.length ?? 0) > 0)
+  .map((r) => [r.name, r] as const);
+
+describe('showcase reports — the subtitle names what the cells hold', () => {
+  it('grades the Status × Priority matrix, among the measure-bound reports', () => {
+    expect(graded.map(([name]) => name)).toContain('showcase_status_priority_matrix');
+  });
+
+  it.each(graded)('%s: the description names a bound measure', (name, report) => {
+    const description = plain(report.description, `${name}.description`).toLowerCase();
+    const named = boundMeasures(report).filter((m) => {
+      const label = plain(m.label, `measure ${m.name}.label`).toLowerCase();
+      return description.includes(label) || (m.aggregate === 'count' && COUNT_WORDS.test(description));
+    });
+    expect(
+      named.map((m) => m.name),
+      `${name}: "${report.description}" names none of its bound measures ${JSON.stringify(report.values)}`,
+    ).not.toEqual([]);
+  });
+
+  it.each(graded)('%s: the description claims no count its cells do not hold', (name, report) => {
+    const description = plain(report.description, `${name}.description`);
+    const bindsACount = boundMeasures(report).some((m) => m.aggregate === 'count');
+    const countWord = description.match(COUNT_WORDS)?.[0];
+    expect(
+      countWord === undefined || bindsACount,
+      `${name}: "${description}" says "${countWord}", but ${JSON.stringify(report.values)} aggregate no count`,
+    ).toBe(true);
+  });
+});