diff --git a/src/agents/pi-embedded-runner/run/attempt.empty-prompt.test.ts b/src/agents/pi-embedded-runner/run/attempt.empty-prompt.test.ts
deleted file mode 100644
index 097547a66f5..00000000000
--- a/src/agents/pi-embedded-runner/run/attempt.empty-prompt.test.ts
+++ /dev/null
@@ -1,64 +0,0 @@
-import type { AgentMessage } from "@mariozechner/pi-agent-core";
-import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
-import {
-  cleanupTempPaths,
-  createContextEngineAttemptRunner,
-  createContextEngineBootstrapAndAssemble,
-  resetEmbeddedAttemptHarness,
-} from "./attempt.spawn-workspace.test-support.js";
-
-describe("runEmbeddedAttempt empty prompt guard", () => {
-  const tempPaths: string[] = [];
-
-  beforeEach(() => {
-    resetEmbeddedAttemptHarness();
-  });
-
-  afterEach(async () => {
-    await cleanupTempPaths(tempPaths);
-    vi.restoreAllMocks();
-  });
-
-  it("skips provider submission when prompt, history, and images are empty", async () => {
-    const sessionPrompt = vi.fn(async () => {});
-    const { assemble } = createContextEngineBootstrapAndAssemble();
-
-    const result = await createContextEngineAttemptRunner({
-      contextEngine: { assemble },
-      sessionKey: "agent:main:guildchat:dm:empty-prompt",
-      tempPaths,
-      sessionMessages: [],
-      sessionPrompt,
-      attemptOverrides: {
-        prompt: "   ",
-      },
-    });
-
-    expect(sessionPrompt).not.toHaveBeenCalled();
-    expect(result.promptError).toBeNull();
-    expect(result.finalPromptText).toBeUndefined();
-    expect(result.messagesSnapshot).toEqual([]);
-    expect(result.assistantTexts).toEqual([]);
-  });
-
-  it("still submits a blank prompt when replay history has content", async () => {
-    const sessionPrompt = vi.fn(async () => {});
-    const { assemble } = createContextEngineBootstrapAndAssemble();
-    const sessionMessages = [
-      { role: "user", content: "previous turn", timestamp: 1 },
-    ] as AgentMessage[];
-
-    await createContextEngineAttemptRunner({
-      contextEngine: { assemble },
-      sessionKey: "agent:main:guildchat:dm:empty-prompt-with-history",
-      tempPaths,
-      sessionMessages,
-      sessionPrompt,
-      attemptOverrides: {
-        prompt: "   ",
-      },
-    });
-
-    expect(sessionPrompt).toHaveBeenCalledTimes(1);
-  });
-});
diff --git a/src/agents/pi-embedded-runner/run/attempt.prompt-helpers.test.ts b/src/agents/pi-embedded-runner/run/attempt.prompt-helpers.test.ts
index c6915703687..55c2556d416 100644
--- a/src/agents/pi-embedded-runner/run/attempt.prompt-helpers.test.ts
+++ b/src/agents/pi-embedded-runner/run/attempt.prompt-helpers.test.ts
@@ -11,7 +11,10 @@ const videoGenerationTaskStatusMocks = vi.hoisted(() => ({
 vi.mock("../../music-generation-task-status.js", () => musicGenerationTaskStatusMocks);
 vi.mock("../../video-generation-task-status.js", () => videoGenerationTaskStatusMocks);
 
-import { resolveAttemptPrependSystemContext } from "./attempt.prompt-helpers.js";
+import {
+  hasPromptSubmissionContent,
+  resolveAttemptPrependSystemContext,
+} from "./attempt.prompt-helpers.js";
 
 describe("resolveAttemptPrependSystemContext", () => {
   it("prepends active video task guidance ahead of hook system context", () => {
@@ -62,3 +65,42 @@ describe("resolveAttemptPrependSystemContext", () => {
     expect(result).toBe("Hook system context");
   });
 });
+
+describe("hasPromptSubmissionContent", () => {
+  it("rejects empty prompt submissions without history or images", () => {
+    expect(
+      hasPromptSubmissionContent({
+        prompt: "   ",
+        messages: [],
+        imageCount: 0,
+      }),
+    ).toBe(false);
+  });
+
+  it("allows blank prompt submissions when replay history has content", () => {
+    expect(
+      hasPromptSubmissionContent({
+        prompt: "   ",
+        messages: [{ role: "user", content: "previous turn", timestamp: 1 }],
+        imageCount: 0,
+      }),
+    ).toBe(true);
+  });
+
+  it("allows text or image prompt submissions", () => {
+    expect(
+      hasPromptSubmissionContent({
+        prompt: "hello",
+        messages: [],
+        imageCount: 0,
+      }),
+    ).toBe(true);
+    expect(
+      hasPromptSubmissionContent({
+        prompt: "   ",
+        messages: [],
+        imageCount: 1,
+      }),
+    ).toBe(true);
+  });
+});
diff --git a/src/agents/pi-embedded-runner/run/attempt.prompt-helpers.ts b/src/agents/pi-embedded-runner/run/attempt.prompt-helpers.ts
index 200153f1ed0..ea7a1214aa2 100644
--- a/src/agents/pi-embedded-runner/run/attempt.prompt-helpers.ts
+++ b/src/agents/pi-embedded-runner/run/attempt.prompt-helpers.ts
@@ -122,6 +122,14 @@ export function shouldWarnOnOrphanedUserRepair(
   return trigger === "user" || trigger === "manual";
 }
 
+export function hasPromptSubmissionContent(params: {
+  prompt: string;
+  messages: readonly unknown[];
+  imageCount: number;
+}): boolean {
+  return params.prompt.trim().length > 0 || params.messages.length > 0 || params.imageCount > 0;
+}
+
 const QUEUED_USER_MESSAGE_MARKER =
   "[Queued user message that arrived while the previous turn was still active]";
 const MAX_STRUCTURED_MEDIA_REF_CHARS = 300;
diff --git a/src/agents/pi-embedded-runner/run/attempt.spawn-workspace.context-engine.test.ts b/src/agents/pi-embedded-runner/run/attempt.spawn-workspace.context-engine.test.ts
index 012e23b60ee..4fbf273db79 100644
--- a/src/agents/pi-embedded-runner/run/attempt.spawn-workspace.context-engine.test.ts
+++ b/src/agents/pi-embedded-runner/run/attempt.spawn-workspace.context-engine.test.ts
@@ -18,7 +18,6 @@ import {
 import {
   cleanupTempPaths,
   createContextEngineBootstrapAndAssemble,
-  createContextEngineAttemptRunner,
   expectCalledWithSessionKey,
   getHoisted,
   resetEmbeddedAttemptHarness,
@@ -277,81 +276,6 @@ describe("runEmbeddedAttempt context engine sessionKey forwarding", () => {
     expect(params.sessionKey).toBe(sessionKey);
   });
 
-  it("prechecks unwindowed context before submitting a windowed context-engine prompt", async () => {
-    const sessionPrompt = vi.fn(async () => {});
-    const fullHistory = [
-      {
-        role: "assistant",
-        content: [{ type: "text", text: "large historical context ".repeat(600) }],
-        timestamp: 1,
-      },
-    ] as AgentMessage[];
-    const windowedMessages = [
-      { role: "assistant", content: [{ type: "text", text: "small window" }], timestamp: 2 },
-    ] as AgentMessage[];
-    const assemble = vi.fn(async () => ({
-      messages: windowedMessages,
-      estimatedTokens: 3,
-    }));
-
-    const result = await createContextEngineAttemptRunner({
-      contextEngine: { assemble },
-      sessionKey,
-      tempPaths,
-      sessionMessages: fullHistory,
-      sessionPrompt,
-      attemptOverrides: {
-        contextTokenBudget: 512,
-      },
-    });
-
-    expect(assemble).toHaveBeenCalledWith(
-      expect.objectContaining({
-        messages: fullHistory,
-      }),
-    );
-    expect(sessionPrompt).not.toHaveBeenCalled();
-    expect(result.promptErrorSource).toBe("precheck");
-    expect(result.preflightRecovery).toEqual({ route: "compact_only" });
-  });
-
-  it("keeps preflight overflow checks active for engines that own compaction", async () => {
-    const sessionPrompt = vi.fn(async () => {});
-    const fullHistory = [
-      {
-        role: "assistant",
-        content: [{ type: "text", text: "engine-owned large historical context ".repeat(600) }],
-        timestamp: 1,
-      },
-    ] as AgentMessage[];
-    const assemble = vi.fn(async () => ({
-      messages: [
-        { role: "assistant", content: [{ type: "text", text: "small window" }], timestamp: 2 },
-      ] as AgentMessage[],
-      estimatedTokens: 3,
-    }));
-
-    const result = await createContextEngineAttemptRunner({
-      contextEngine: {
-        assemble,
-        info: {
-          ownsCompaction: true,
-        },
-      },
-      sessionKey,
-      tempPaths,
-      sessionMessages: fullHistory,
-      sessionPrompt,
-      attemptOverrides: {
-        contextTokenBudget: 512,
-      },
-    });
-
-    expect(sessionPrompt).not.toHaveBeenCalled();
-    expect(result.promptErrorSource).toBe("precheck");
-    expect(result.preflightRecovery).toEqual({ route: "compact_only" });
-  });
-
   it("skips maintenance when afterTurn fails", async () => {
     const { bootstrap, assemble } = createContextEngineBootstrapAndAssemble();
     const afterTurn = vi.fn(async () => {
diff --git a/src/agents/pi-embedded-runner/run/attempt.ts b/src/agents/pi-embedded-runner/run/attempt.ts
index 60f51f76e19..5bb325ed5c0 100644
--- a/src/agents/pi-embedded-runner/run/attempt.ts
+++ b/src/agents/pi-embedded-runner/run/attempt.ts
@@ -252,6 +252,7 @@ import {
   resolveAttemptPrependSystemContext,
   resolvePromptBuildHookResult,
   resolvePromptModeForSession,
+  hasPromptSubmissionContent,
   shouldWarnOnOrphanedUserRepair,
   shouldInjectHeartbeatPrompt,
 } from "./attempt.prompt-helpers.js";
@@ -453,14 +454,6 @@ function summarizeSessionContext(messages: AgentMessage[]): {
   };
 }
 
-function hasPromptSubmissionContent(params: {
-  prompt: string;
-  messages: readonly AgentMessage[];
-  imageCount: number;
-}): boolean {
-  return params.prompt.trim().length > 0 || params.messages.length > 0 || params.imageCount > 0;
-}
-
 export function applyEmbeddedAttemptToolsAllow<T extends { name: string }>(
   tools: T[],
   toolsAllow?: string[],