diff --git a/packages/adapters/grok-local/src/server/test.test.ts b/packages/adapters/grok-local/src/server/test.test.ts
index 6800744b6f..e2d9e495c7 100644
--- a/packages/adapters/grok-local/src/server/test.test.ts
+++ b/packages/adapters/grok-local/src/server/test.test.ts
@@ -105,6 +105,84 @@ describe("grok_local testEnvironment", () => {
     );
   });
 
+  it("does not warn when the default-sentinel model is absent from the real model list", async () => {
+    // Real grok never lists the "grok-build" sentinel; execute.ts never sends
+    // it. The probe must treat the default as valid (info), not warn.
+    runProcessMock
+      .mockResolvedValueOnce({
+        exitCode: 0,
+        signal: null,
+        timedOut: false,
+        stdout: [
+          "You are logged in with grok.com.",
+          "",
+          "Default model: grok-4.20-0309-non-reasoning",
+          "",
+          "Available models:",
+          "  * grok-4.20-0309-non-reasoning (default)",
+          "  * grok-4",
+        ].join("\n"),
+        stderr: "",
+      })
+      .mockResolvedValueOnce({
+        exitCode: 0,
+        signal: null,
+        timedOut: false,
+        stdout: [
+          JSON.stringify({ type: "text", data: "hello" }),
+          JSON.stringify({ type: "end", stopReason: "EndTurn", sessionId: "s", requestId: "r" }),
+        ].join("\n"),
+        stderr: "",
+      });
+
+    const result = await testEnvironment({
+      companyId: "company-1",
+      adapterType: "grok_local",
+      config: { command: "grok", cwd: "/tmp/project" }, // no model → default sentinel
+    });
+
+    const codes = result.checks.map((check: { code: string }) => check.code);
+    expect(codes).toContain("grok_model_configured");
+    expect(codes).not.toContain("grok_model_not_found");
+    expect(result.status).toBe("pass");
+  });
+
+  it("warns when an explicitly configured real model is not available", async () => {
+    runProcessMock
+      .mockResolvedValueOnce({
+        exitCode: 0,
+        signal: null,
+        timedOut: false,
+        stdout: [
+          "You are logged in with grok.com.",
+          "",
+          "Default model: grok-4",
+          "",
+          "Available models:",
+          "  * grok-4",
+        ].join("\n"),
+        stderr: "",
+      })
+      .mockResolvedValueOnce({
+        exitCode: 0,
+        signal: null,
+        timedOut: false,
+        stdout: [
+          JSON.stringify({ type: "text", data: "hello" }),
+          JSON.stringify({ type: "end", stopReason: "EndTurn", sessionId: "s", requestId: "r" }),
+        ].join("\n"),
+        stderr: "",
+      });
+
+    const result = await testEnvironment({
+      companyId: "company-1",
+      adapterType: "grok_local",
+      config: { command: "grok", cwd: "/tmp/project", model: "grok-nonexistent" },
+    });
+
+    expect(result.checks.map((check: { code: string }) => check.code)).toContain("grok_model_not_found");
+  });
+
   it("downgrades auth failures to warnings", async () => {
     runProcessMock
       .mockResolvedValueOnce({
diff --git a/packages/adapters/grok-local/src/server/test.ts b/packages/adapters/grok-local/src/server/test.ts
index b69ad7ff6c..f166d3c6af 100644
--- a/packages/adapters/grok-local/src/server/test.ts
+++ b/packages/adapters/grok-local/src/server/test.ts
@@ -226,15 +226,22 @@ export async function testEnvironment(
         });
       }
       if (configuredModel) {
+        // The default model id is a sentinel meaning "let the Grok CLI pick its
+        // own default" — execute.ts only passes `--model` when the value differs
+        // from it, so the sentinel is never sent to grok and must not be checked
+        // against the discovered list (real grok never lists "grok-build", which
+        // otherwise produced a spurious "not found" warning on every probe).
+        const usesCliDefault = configuredModel === DEFAULT_GROK_LOCAL_MODEL;
+        const available = usesCliDefault || parsedModels.models.includes(configuredModel);
         checks.push({
-          code: parsedModels.models.includes(configuredModel) ? "grok_model_configured" : "grok_model_not_found",
-          level: parsedModels.models.includes(configuredModel) ? "info" : "warn",
-          message: parsedModels.models.includes(configuredModel)
-            ? `Configured model: ${configuredModel}`
-            : `Configured model "${configuredModel}" not found in available models.`,
-          hint: parsedModels.models.includes(configuredModel)
-            ? undefined
-            : "Run `grok models` and choose an available model id.",
+          code: available ? "grok_model_configured" : "grok_model_not_found",
+          level: available ? "info" : "warn",
+          message: usesCliDefault
+            ? `Using the Grok CLI's default model${parsedModels.defaultModel ? ` (${parsedModels.defaultModel})` : ""}.`
+            : available
+              ? `Configured model: ${configuredModel}`
+              : `Configured model "${configuredModel}" not found in available models.`,
+          hint: available ? undefined : "Run `grok models` and choose an available model id.",
         });
       }
     }