diff --git a/src/agents/pi-tools.ts b/src/agents/pi-tools.ts
index 0db567ce6..df08e0a7a 100644
--- a/src/agents/pi-tools.ts
+++ b/src/agents/pi-tools.ts
@@ -430,7 +430,7 @@ function wrapSandboxPathGuard(tool: AnyAgentTool, root: string): AnyAgentTool {
 }
 
 type RequiredParamGroup = {
-  keys: string[];
+  keys: readonly string[];
   allowEmpty?: boolean;
   label?: string;
 };
diff --git a/src/plugins/voice-call.plugin.test.ts b/src/plugins/voice-call.plugin.test.ts
index 51d0a2807..14ab710b1 100644
--- a/src/plugins/voice-call.plugin.test.ts
+++ b/src/plugins/voice-call.plugin.test.ts
@@ -124,7 +124,7 @@ describe("voice-call plugin", () => {
       action: "get_status",
       callId: "call-1",
     });
-    expect(result.details.found).toBe(true);
+    expect((result.details as { found?: boolean }).found).toBe(true);
   });
 
   it("legacy tool status without sid returns error payload", async () => {
@@ -141,7 +141,9 @@ describe("voice-call plugin", () => {
     };
     const tool = tools[0] as VoiceTool;
     const result = await tool.execute("id", { mode: "status" });
-    expect(String(result.details.error)).toContain("sid required");
+    expect(String((result.details as { error?: unknown }).error)).toContain(
+      "sid required",
+    );
   });
 
   it("CLI start prints JSON", async () => {