diff --git a/scripts/research_workflow.py b/scripts/research_workflow.py
index ee7b82bc5..7079107a0 100644
--- a/scripts/research_workflow.py
+++ b/scripts/research_workflow.py
@@ -124,6 +124,37 @@ def slug(value):
     return value
 
 
+def load_outline(path):
+    """Load an --outline file, rejecting wrong shapes via fail().
+
+    Every rejection names the outline file and the field/expectation, so
+    a malformed outline produces the tool's clean diagnostic instead of
+    a raw AttributeError/TypeError/JSONDecodeError from deep in
+    scaffold() (issue #6862).
+    """
+    try:
+        outline = json.loads(Path(path).read_text())
+    except json.JSONDecodeError as error:
+        fail(f"Outline {path} is not valid JSON: {error}")
+    if not isinstance(outline, dict):
+        fail(f"Outline {path} must be a JSON object at the top level")
+    for field in ("title", "introduction"):
+        if field in outline and not isinstance(outline[field], str):
+            fail(f"Outline {path} field '{field}' must be a string")
+    concepts = outline.get("concepts")
+    if isinstance(concepts, list):
+        for index, concept in enumerate(concepts, 1):
+            if not isinstance(concept, dict):
+                fail(f"Outline {path} concept {index} must be a JSON object")
+            for field in ("slug", "summary"):
+                if field in concept and not isinstance(concept[field], str):
+                    fail(
+                        f"Outline {path} concept {index} field '{field}'"
+                        " must be a string"
+                    )
+    return outline
+
+
 def marker(kind, data):
     payload = json.dumps(data, ensure_ascii=False, indent=2).replace("<", "\\u003c")
     return f"<!-- workflow:{kind} -->\n{payload}\n<!-- /workflow:{kind} -->\n"
@@ -241,7 +272,7 @@ def scaffold(args, root, config):
     if package.exists() or package.is_symlink():
         fail(f"Package already exists: {package}")
     outline = (
-        json.loads(Path(args.outline).read_text())
+        load_outline(args.outline)
         if args.outline
         else {
             "title": args.concept or args.slug.replace("-", " ").title(),
diff --git a/scripts/tests/test_research_workflow.py b/scripts/tests/test_research_workflow.py
index 1d25df87f..9e576fda6 100644
--- a/scripts/tests/test_research_workflow.py
+++ b/scripts/tests/test_research_workflow.py
@@ -273,6 +273,80 @@ def test_duplicate_concept_slugs_are_rejected_before_any_creation(self):
         self.init(outline=outline, ok=False)
         self.assertEqual(self.snapshot(), before)
 
+    def test_outline_top_level_must_be_an_object(self):
+        before = self.snapshot()
+        result = self.init(outline=[], ok=False)
+        self.assertIn("outline.json", result.stderr)
+        self.assertIn("must be a JSON object", result.stderr)
+        self.assertEqual(self.snapshot(), before)
+
+    def test_outline_non_json_names_the_file(self):
+        self.outline_file = self.scratch / "outline.json"
+        self.outline_file.write_text("this is not json", encoding="utf-8")
+        before = self.snapshot()
+        result = self.cli(
+            "init",
+            "--repo-root",
+            self.root,
+            "--input",
+            self.input,
+            "--slug",
+            "assorted-ideas",
+            "--timestamp",
+            TIMESTAMP,
+            "--outline",
+            self.outline_file,
+            ok=False,
+        )
+        self.assertIn("outline.json", result.stderr)
+        self.assertIn("is not valid JSON", result.stderr)
+        self.assertEqual(self.snapshot(), before)
+
+    def test_outline_title_must_be_a_string(self):
+        outline = self.outline()
+        outline["title"] = 42
+        before = self.snapshot()
+        result = self.init(outline=outline, ok=False)
+        self.assertIn("outline.json", result.stderr)
+        self.assertIn("'title' must be a string", result.stderr)
+        self.assertEqual(self.snapshot(), before)
+
+    def test_outline_introduction_must_be_a_string(self):
+        outline = self.outline()
+        outline["introduction"] = 42
+        before = self.snapshot()
+        result = self.init(outline=outline, ok=False)
+        self.assertIn("outline.json", result.stderr)
+        self.assertIn("'introduction' must be a string", result.stderr)
+        self.assertEqual(self.snapshot(), before)
+
+    def test_outline_concept_entries_must_be_objects(self):
+        outline = self.outline()
+        outline["concepts"][0] = "just-a-string"
+        before = self.snapshot()
+        result = self.init(outline=outline, ok=False)
+        self.assertIn("outline.json", result.stderr)
+        self.assertIn("concept 1 must be a JSON object", result.stderr)
+        self.assertEqual(self.snapshot(), before)
+
+    def test_outline_concept_slug_must_be_a_string(self):
+        outline = self.outline()
+        outline["concepts"][0]["slug"] = 42
+        before = self.snapshot()
+        result = self.init(outline=outline, ok=False)
+        self.assertIn("outline.json", result.stderr)
+        self.assertIn("'slug' must be a string", result.stderr)
+        self.assertEqual(self.snapshot(), before)
+
+    def test_outline_concept_summary_must_be_a_string(self):
+        outline = self.outline()
+        outline["concepts"][0]["summary"] = 42
+        before = self.snapshot()
+        result = self.init(outline=outline, ok=False)
+        self.assertIn("outline.json", result.stderr)
+        self.assertIn("'summary' must be a string", result.stderr)
+        self.assertEqual(self.snapshot(), before)
+
     def test_existing_package_collision_never_overwrites_completed_intake(self):
         self.init()
         before = self.snapshot()