diff --git a/extensions/workboard/src/gateway.test.ts b/extensions/workboard/src/gateway.test.ts
index 958e9da3c9f2..5e35c6acae76 100644
--- a/extensions/workboard/src/gateway.test.ts
+++ b/extensions/workboard/src/gateway.test.ts
@@ -339,7 +339,7 @@ describe("workboard gateway methods", () => {
 
     expect(respond.mock.calls[0]?.[0]).toBe(false);
     expect(respond.mock.calls[0]?.[2]).toMatchObject({
-      message: expect.stringMatching(/^labels must be 40 characters or fewer(?: \(got 41\))?\.$/),
+      message: "labels must be 40 characters or fewer.",
     });
   });
 
diff --git a/extensions/workboard/src/store-normalizers.test.ts b/extensions/workboard/src/store-normalizers.test.ts
index 2454363cb269..603ec0806e3b 100644
--- a/extensions/workboard/src/store-normalizers.test.ts
+++ b/extensions/workboard/src/store-normalizers.test.ts
@@ -1,7 +1,10 @@
 // Regression coverage for the bounded-string normalizer used across Workboard
-// input validators. The helper is shared by comment, label, title, url, and
-// other bounded fields; an opaque error message blocks agents that overshoot
-// the limit because they cannot tell how far over they are.
+// input validators. The helper is shared by comment body, card id, link
+// target, link URL, and link title; an opaque error message blocks agents
+// that overshoot the limit because they cannot tell how far over they are.
+// Title / notes / labels use their own independent validators and emit
+// generic error messages that are intentionally out of scope for this
+// helper.
 import { describe, expect, it } from "vitest";
 import { normalizeBoundedString } from "./store-normalizers.js";
 
@@ -26,19 +29,24 @@ describe("normalizeBoundedString", () => {
   });
 
   it("keeps the error message length-aware for every bounded field", () => {
-    // title/notes/labels/targetCardId/url/title are bounded through the same
-    // helper. A regression that drops the (got N) suffix will fail here.
+    // The `normalizeBoundedString` helper is the shared diagnostic owner for
+    // comment body, card id, link target, link URL, and link title. A
+    // regression that drops the (got N) suffix will fail here.
+    //
+    // Note: `normalizeTitle`, `normalizeNotes`, and `normalizeLabels` are
+    // independent validators with their own generic error messages, not
+    // consumers of this helper, so they are intentionally excluded from
+    // this matrix. Closes the false-confidence gap that ClawSweeper
+    // flagged on the prior matrix.
     const cases: ReadonlyArray<{
       readonly field: string;
       readonly limit: number;
       readonly actual: number;
     }> = [
-      { field: "labels", limit: 40, actual: 41 },
       { field: "link title", limit: 180, actual: 181 },
-      { field: "title", limit: 180, actual: 9999 },
-      { field: "notes", limit: 4000, actual: 4001 },
       { field: "link target", limit: 120, actual: 121 },
       { field: "link URL", limit: 2000, actual: 2001 },
+      { field: "card id", limit: 120, actual: 121 },
     ];
     for (const c of cases) {
       const overlong = "x".repeat(c.actual);