diff --git a/packages/tui/src/routes/session/index.tsx b/packages/tui/src/routes/session/index.tsx
index 6d77b0ea58fd..b101005dc209 100644
--- a/packages/tui/src/routes/session/index.tsx
+++ b/packages/tui/src/routes/session/index.tsx
@@ -214,13 +214,7 @@ export function Session() {
   const foregroundTasks = createMemo(() =>
     sync.data.capabilities.experimentalBackgroundSubagents
       ? messages().flatMap((message) =>
-          (sync.data.part[message.id] ?? []).filter(
-            (part): part is ToolPart =>
-              part.type === "tool" &&
-              part.tool === "task" &&
-              part.state.status === "running" &&
-              part.state.metadata?.background !== true,
-          ),
+          (sync.data.part[message.id] ?? []).filter(isForegroundRunningTask),
         )
       : [],
   )
@@ -1500,13 +1494,7 @@ function AssistantMessage(props: { message: AssistantMessage; parts: Part[]; las
             <Show
               when={
                 sync.data.capabilities.experimentalBackgroundSubagents &&
-                props.parts.some(
-                  (x) =>
-                    x.type === "tool" &&
-                    x.tool === "task" &&
-                    x.state.status === "running" &&
-                    x.state.metadata?.background !== true,
-                )
+                props.parts.some(isForegroundRunningTask)
               }
             >
               <span style={{ fg: theme.textMuted }}> · </span>
@@ -2708,3 +2696,13 @@ export function parseDiagnostics(value: unknown, filePath: string) {
     })
     .slice(0, 3)
 }
+
+export function isForegroundRunningTask(part: Part): part is ToolPart {
+  return (
+    part.type === "tool" &&
+    part.tool === "task" &&
+    part.state.status === "running" &&
+    part.state.metadata?.background !== true &&
+    part.state.input?.background !== true
+  )
+}
diff --git a/packages/tui/test/cli/tui/background-tool-hint.test.ts b/packages/tui/test/cli/tui/background-tool-hint.test.ts
new file mode 100644
index 000000000000..ee4d56539775
--- /dev/null
+++ b/packages/tui/test/cli/tui/background-tool-hint.test.ts
@@ -0,0 +1,79 @@
+import { expect, test } from "bun:test"
+import type { Part, ToolPart } from "@opencode-ai/sdk/v2"
+import { isForegroundRunningTask } from "../../../src/routes/session"
+
+function taskPart(opts: { background?: boolean; metadataBackground?: boolean } = {}): Part {
+  return {
+    id: "part-1",
+    sessionID: "session-1",
+    messageID: "message-1",
+    type: "tool",
+    callID: "call-1",
+    tool: "task",
+    state: {
+      status: "running",
+      input: opts.background ? { background: true } : {},
+      metadata: opts.metadataBackground ? { background: true } : undefined,
+      time: { start: Date.now() },
+    },
+  } satisfies ToolPart as Part
+}
+
+function nonTaskPart(tool: string): Part {
+  return {
+    id: "part-2",
+    sessionID: "session-1",
+    messageID: "message-1",
+    type: "tool",
+    callID: "call-2",
+    tool,
+    state: {
+      status: "running",
+      input: {},
+      time: { start: Date.now() },
+    },
+  } satisfies ToolPart as Part
+}
+
+test("returns true for a foreground running task", () => {
+  expect(isForegroundRunningTask(taskPart())).toBeTrue()
+})
+
+test("returns false when input.background is true", () => {
+  expect(isForegroundRunningTask(taskPart({ background: true }))).toBeFalse()
+})
+
+test("returns false when metadata.background is true", () => {
+  expect(isForegroundRunningTask(taskPart({ metadataBackground: true }))).toBeFalse()
+})
+
+test("returns false when both input and metadata mark background", () => {
+  expect(isForegroundRunningTask(taskPart({ background: true, metadataBackground: true }))).toBeFalse()
+})
+
+test("returns false for non-task tools", () => {
+  expect(isForegroundRunningTask(nonTaskPart("read"))).toBeFalse()
+  expect(isForegroundRunningTask(nonTaskPart("write"))).toBeFalse()
+  expect(isForegroundRunningTask(nonTaskPart("bash"))).toBeFalse()
+})
+
+test("returns false for a completed task", () => {
+  const part = {
+    id: "part-3",
+    sessionID: "session-1",
+    messageID: "message-1",
+    type: "tool" as const,
+    callID: "call-3",
+    tool: "task",
+    state: {
+      status: "completed" as const,
+      input: {},
+      output: "",
+      title: "",
+      metadata: {},
+      time: { start: Date.now(), end: Date.now() },
+      content: [],
+    },
+  } as Part
+  expect(isForegroundRunningTask(part)).toBeFalse()
+})