diff --git a/src/lib/account-region.ts b/src/lib/account-region.ts
index 00bc9be5..5ea14bb7 100644
--- a/src/lib/account-region.ts
+++ b/src/lib/account-region.ts
@@ -119,6 +119,7 @@ async function probe(
       `${config["browserstack-username"]}:${config["browserstack-access-key"]}`,
     ).toString("base64");
   let rejected = 0;
+  const answers: string[] = [];
   for (const [region, host] of PROBE_HOSTS) {
     try {
       const res = await apiClient.get({
@@ -129,10 +130,13 @@ async function probe(
       });
       if (res.ok) return region;
       if (res.status === 401) rejected++;
+      answers.push(`${region} ${res.status}`);
     } catch (error) {
       logger.debug(`Region probe failed for ${host}: ${error}`);
+      answers.push(`${region} unreachable`);
     }
   }
+  logger.warn(`No region probe accepted the account: ${answers.join(", ")}`);
   return rejected === PROBE_HOSTS.length ? "rejected" : null;
 }
 
diff --git a/src/lib/instrumentation.ts b/src/lib/instrumentation.ts
index 699c6815..1ce360ad 100644
--- a/src/lib/instrumentation.ts
+++ b/src/lib/instrumentation.ts
@@ -102,11 +102,14 @@ function forDataRegion(
   account: AccountRegion | undefined,
 ): MCPEventPayload["event_properties"] {
   if (!isRestrictedRegion(account)) return props;
+  const keepsErrorText = account === "unknown";
   return Object.fromEntries(
     Object.entries(props).filter(
       // A product name the agent typed is free text, so only a known product is kept.
       ([key, value]) =>
-        USAGE_FIELDS.has(key) && (key !== "product" || isKnownProduct(value)),
+        (USAGE_FIELDS.has(key) &&
+          (key !== "product" || isKnownProduct(value))) ||
+        (keepsErrorText && key === "error_message"),
     ),
   ) as MCPEventPayload["event_properties"];
 }
diff --git a/tests/lib/account-region-behaviour.test.ts b/tests/lib/account-region-behaviour.test.ts
index b101f27e..33b5c4a7 100644
--- a/tests/lib/account-region-behaviour.test.ts
+++ b/tests/lib/account-region-behaviour.test.ts
@@ -93,13 +93,13 @@ describe("the account's region", () => {
   });
 
   it.each([
-    ["eu", true],
-    ["unknown", true],
-    ["us", false],
-    ["in", true],
+    ["eu", false, false],
+    ["unknown", true, false],
+    ["us", true, true],
+    ["in", false, false],
   ])(
-    "limits telemetry outside a tool call for a %s account: %s",
-    async (region, limited) => {
+    "limits telemetry outside a tool call for a %s account",
+    async (region, errorText, freeText) => {
       regions.set("user", region);
       trackMCP("started", clientInfo, new Error("boom"), configFor("user"), {
         search_query: "checkout runs",
@@ -107,8 +107,8 @@ describe("the account's region", () => {
       await settle();
       const row = rows().at(-1);
       expect(row.tool_name).toBe("started");
-      expect("error_message" in row).toBe(!limited);
-      expect("search_query" in row).toBe(!limited);
+      expect("error_message" in row).toBe(errorText);
+      expect("search_query" in row).toBe(freeText);
     },
   );
 
diff --git a/tests/lib/instrumentation-grr-region.test.ts b/tests/lib/instrumentation-grr-region.test.ts
index cbcf6aab..7806b67e 100644
--- a/tests/lib/instrumentation-grr-region.test.ts
+++ b/tests/lib/instrumentation-grr-region.test.ts
@@ -24,7 +24,44 @@ const lastRow = () =>
 describe("telemetry by the account's region", () => {
   beforeEach(() => vi.clearAllMocks());
 
-  it.each(["eu", "in", "unknown"])(
+  it("keeps only usage fields and the error text when the region is unknown", () => {
+    withAccountRegion("unknown", () =>
+      trackMCP("invokeCapability", clientInfo, new Error("boom"), config, {
+        capability: "listTestRuns",
+        change_summary: "close the checkout regression run",
+        search_query: "checkout runs",
+        feedback_message: "it failed",
+      }),
+    );
+    const row = lastRow();
+    expect(row).toMatchObject({
+      error_type: "Error",
+      error_message: "boom",
+      capability: "listTestRuns",
+    });
+    for (const field of ["change_summary", "search_query", "feedback_message"])
+      expect(row).not.toHaveProperty(field);
+  });
+
+  it("keeps the error text of a returned failure when the region is unknown", async () => {
+    await withAccountRegion("unknown", () =>
+      withToolCall(
+        "listTestCases",
+        () => clientInfo,
+        config,
+        async () => ({
+          content: [{ type: "text", text: "Project PR-1 not found" }],
+          isError: true,
+        }),
+      ),
+    );
+    expect(lastRow()).toMatchObject({
+      outcome: "error_result",
+      error_message: "Project PR-1 not found",
+    });
+  });
+
+  it.each(["eu", "in"])(
     "drops free text but keeps usage fields for a %s account",
     (region) => {
       withAccountRegion(region as any, () =>
@@ -57,7 +94,7 @@ describe("telemetry by the account's region", () => {
     },
   );
 
-  it.each(["eu", "in", "unknown"])(
+  it.each(["eu", "in"])(
     "drops the error text of a returned failure for a %s account",
     async (region) => {
       await withAccountRegion(region as any, () =>