Improve extract error formatting and warning output

Co-authored-by: Shri Sukhani <shrisukhani@users.noreply.github.com>

Author: cursoragent

src/agent/actions/extract.test.ts

@@ -147,4 +147,16 @@ describe("ExtractActionDefinition.run", () => {
     expect(result.success).toBe(false);
     expect(result.message).toContain("No content extracted");
   });
+
+  it("returns formatted root error messages", async () => {
+    parseMarkdown.mockRejectedValue(new Error("markdown parse failed"));
+    const ctx = createContext();
+
+    const result = await ExtractActionDefinition.run(ctx, {
+      objective: "Extract content",
+    });
+
+    expect(result.success).toBe(false);
+    expect(result.message).toContain("markdown parse failed");
+  });
 });

src/agent/actions/extract.ts

@@ -76,6 +76,10 @@ function writeDebugFileSafe(
   }
 }
 
+function formatErrorMessage(error: unknown): string {
+  return error instanceof Error ? error.message : String(error);
+}
+
 export const ExtractActionDefinition: AgentActionDefinition = {
   type: "extract" as const,
   actionParams: ExtractAction,
@@ -101,7 +105,7 @@ export const ExtractActionDefinition: AgentActionDefinition = {
         if (ctx.debug) {
           console.warn(
             "[extract] Screenshot capture unavailable, falling back to markdown-only extraction:",
-            error
+            formatErrorMessage(error)
           );
         }
       }
@@ -172,7 +176,7 @@ export const ExtractActionDefinition: AgentActionDefinition = {
     } catch (error) {
       return {
         success: false,
-        message: `Failed to extract content: ${error}`,
+        message: `Failed to extract content: ${formatErrorMessage(error)}`,
       };
     }
   },