diff --git a/src/application/WebScriptExportService.ts b/src/application/WebScriptExportService.ts
index c0a52b351a..d0cd45ea31 100644
--- a/src/application/WebScriptExportService.ts
+++ b/src/application/WebScriptExportService.ts
@@ -85,16 +85,20 @@ export const exportWebScriptsValidated = async (
   resources: ArtifactResourceScope,
   options: ExecutionOptions = {},
 ): Promise<Result<Evidence, AnalysisError>> => {
-  if (!isAbsolute(input.capture_path) || !isAbsolute(input.output_directory))
+  const invalidPaths = (["capture_path", "output_directory"] as const).filter(
+    (field) => !isAbsolute(input[field]),
+  );
+  if (invalidPaths.length > 0)
     return err(
-      new AnalysisInputError(OPERATION, undefined, [
-        {
-          path: [],
-          reason: "invalid_format",
-          message:
-            "capture_path and output_directory must be absolute filesystem paths on this host.",
-        },
-      ]),
+      new AnalysisInputError(
+        OPERATION,
+        undefined,
+        invalidPaths.map((field) => ({
+          path: [field],
+          reason: "invalid_format" as const,
+          message: `${field} must be an absolute filesystem path on this host.`,
+        })),
+      ),
     );
   try {
     if (options.signal?.aborted)
diff --git a/tests/boundary/filesystem/webScriptExport.test.ts b/tests/boundary/filesystem/webScriptExport.test.ts
index 24fd34ad11..942ca7ae3a 100644
--- a/tests/boundary/filesystem/webScriptExport.test.ts
+++ b/tests/boundary/filesystem/webScriptExport.test.ts
@@ -761,7 +761,9 @@ describe("captured script final commit cancellation", () => {
       });
     },
   );
+});
 
+describe("captured script path validation", () => {
   it("identifies a missing capture file and rejected host path syntax", async () => {
     const { input, resources } = await setup();
     const missing = await exportWebScripts(
@@ -784,15 +786,67 @@ describe("captured script final commit cancellation", () => {
         ],
       },
     });
-    const relative = await exportWebScripts(
+    const relativeCapture = await exportWebScripts(
       {
         ...input,
         capture_path: "capture.json",
       },
       resources,
     );
-    if (relative.ok) throw new Error("Expected host path error");
-    expect(relative.error._tag).toBe("AnalysisInputError");
+    if (relativeCapture.ok) throw new Error("Expected host path error");
+    expect(relativeCapture.error).toMatchObject({
+      _tag: "AnalysisInputError",
+      issues: [
+        {
+          path: ["capture_path"],
+          reason: "invalid_format",
+          message:
+            "capture_path must be an absolute filesystem path on this host.",
+        },
+      ],
+    });
+
+    const relativeOutput = await exportWebScripts(
+      {
+        ...input,
+        output_directory: "dist",
+      },
+      resources,
+    );
+    if (relativeOutput.ok) throw new Error("Expected host path error");
+    expect(relativeOutput.error).toMatchObject({
+      _tag: "AnalysisInputError",
+      issues: [
+        {
+          path: ["output_directory"],
+          reason: "invalid_format",
+          message:
+            "output_directory must be an absolute filesystem path on this host.",
+        },
+      ],
+    });
+
+    const bothRelative = await exportWebScripts(
+      {
+        capture_path: "capture.json",
+        output_directory: "dist",
+      },
+      resources,
+    );
+    if (bothRelative.ok) throw new Error("Expected host path error");
+    expect(bothRelative.error).toMatchObject({
+      _tag: "AnalysisInputError",
+      issues: [
+        {
+          path: ["capture_path"],
+          reason: "invalid_format",
+        },
+        {
+          path: ["output_directory"],
+          reason: "invalid_format",
+        },
+      ],
+    });
   });
 });