test(prompts): promptResidual appended once for grok leaf

Author: TheGreatAxios

src/agent/model-family-policy.test.ts

@@ -102,4 +102,31 @@ describe("resolveModelFamilyPolicy", () => {
     expect(muse.toolDisciplineRules).toContain("Never re-read a file");
     expect(base.toolDisciplineRules).toBeUndefined();
   });
+
+  describe("promptResidual (CL-8297)", () => {
+    test("grok leaf carries the generic 4-line tool-budget residual", () => {
+      const leaf = resolveModelFamilyPolicy({
+        providerName: "xai/default",
+        model: "grok-4.6",
+      });
+      expect(leaf.family).toBe("grok");
+      expect(leaf.promptResidual).toBeDefined();
+      expect(leaf.promptResidual!.split("\n")).toHaveLength(4);
+      expect(leaf.promptResidual).toContain("Tool budget:");
+    });
+
+    test("grok orchestrators and default family carry no residual", () => {
+      const orchestrator = resolveModelFamilyPolicy({
+        providerName: "xai/default",
+        model: "grok-4.6",
+        orchestrator: true,
+      });
+      expect(orchestrator.promptResidual).toBeUndefined();
+      const base = resolveModelFamilyPolicy({
+        providerName: "anthropic",
+        model: "claude-sonnet-4",
+      });
+      expect(base.promptResidual).toBeUndefined();
+    });
+  });
 });

src/agent/prompt-sizes.test.ts

@@ -332,3 +332,22 @@ describe("skywalker grok prefix (infer envelope vs trimmed director)", () => {
     }
   });
 });
+
+describe("grok tool-budget residual (CL-8297)", () => {
+  const countOccurrences = (haystack: string, needle: string): number =>
+    haystack.split(needle).length - 1;
+
+  test("a grok leaf director prompt contains the tool budget exactly once", () => {
+    const prompt = assembleDirectorPrompt("builder", "grok");
+    expect(countOccurrences(prompt, "Tool budget:")).toBe(1);
+  });
+
+  test("default-family and orchestrator prompts carry no tool budget", () => {
+    expect(assembleDirectorPrompt("builder", "default")).not.toContain(
+      "Tool budget:",
+    );
+    expect(assembleDirectorPrompt("skywalker", "grok")).not.toContain(
+      "Tool budget:",
+    );
+  });
+});

src/agent/prompts.test.ts

@@ -370,3 +370,29 @@ describe("grok finish-bias residual gating (extends existing provider-family tes
     expect(prompt.toLowerCase()).not.toContain("kimi");
   });
 });
+
+describe("promptResidual assembly (CL-8297)", () => {
+  const TOOL_BUDGET =
+    "Tool budget:\n" +
+    "- Batch independent tool calls into a single turn.\n" +
+    "- Never re-issue a tool call whose result you already have.\n" +
+    "- When the next call would only repeat prior work, write the report instead.";
+
+  it("appends promptResidual exactly once at the tail for a grok leaf", () => {
+    const prompt = buildSubAgentSystemPrompt(undefined, undefined, undefined, {
+      orchestrator: false,
+      grokAntiThrash: true,
+      promptResidual: TOOL_BUDGET,
+    });
+    expect(countOccurrences(prompt, TOOL_BUDGET)).toBe(1);
+    expect(prompt.trimEnd().endsWith(TOOL_BUDGET)).toBe(true);
+  });
+
+  it("omits the tool budget when promptResidual is unset", () => {
+    const prompt = buildSubAgentSystemPrompt(undefined, undefined, undefined, {
+      orchestrator: false,
+      grokAntiThrash: true,
+    });
+    expect(prompt).not.toContain("Tool budget:");
+  });
+});