diff --git a/tools/story_flags.py b/tools/story_flags.py
index b2e9c3c..f43e4cc 100644
--- a/tools/story_flags.py
+++ b/tools/story_flags.py
@@ -126,6 +126,44 @@ def write_candidates(cands: dict[int, dict]) -> Path:
     return p
 
 
+import globals_build as _gb
+
+
+def skeleton_toml(ev: dict) -> str:
+    consts = ", ".join(str(c) for c in ev["consts"][:8])
+    domain = "{0,1}" if set(ev["consts"]) <= {0, 1} and ev["consts"] else (f"one of {{{consts}}}" if consts else "?")
+    usage = (f"TODO: confirm. Branch-read in {ev['reach_scenes']} scenes / {ev['reach_total']} scripts; "
+             f"compared against [{consts}]; "
+             f"writers={ev['writers'][:4] or 'none (external/native?)'}.")
+    lines = ["[[global]]",
+             f'address = "{ev["address"]}"',
+             'name = ""',
+             f'category = "{ev["category"]}"',
+             'type = "int"',
+             f'value_domain = "{domain}"',
+             f'usage = "{usage}"',
+             'source = "auto-shape"',
+             f'confidence = "{ev["confidence"]}"',
+             "depends_on = []"]
+    return "\n".join(lines) + "\n"
+
+
+def bootstrap(cands: dict[int, dict], toml_path=None) -> int:
+    toml_path = Path(toml_path) if toml_path else (paths.VM_MAP / "globals.toml")
+    present = set(_gb.load_toml(toml_path)[0]) if toml_path.exists() else set()
+    # only story-flag / ui-toggle / choice-output candidates are worth seeding for curation
+    seedable = {a: e for a, e in cands.items()
+                if e["category"] in ("story-flag", "ui-toggle", "choice-output") and a not in present}
+    if not seedable:
+        print(f"bootstrap: nothing new to add ({len(present)} already present).")
+        return 0
+    blocks = [skeleton_toml(seedable[a]) for a in sorted(seedable)]
+    with toml_path.open("a", encoding="utf-8") as f:
+        f.write("\n" + "\n".join(blocks))
+    print(f"bootstrap: appended {len(blocks)} skeletons -> {toml_path}")
+    return 0
+
+
 def main(argv=None):
     ap = argparse.ArgumentParser()
     ap.add_argument("--bootstrap", action="store_true")   # implemented in Task 5
diff --git a/tools/test_globals.py b/tools/test_globals.py
index 8b0f483..f7bc9de 100644
--- a/tools/test_globals.py
+++ b/tools/test_globals.py
@@ -58,11 +58,35 @@ def test_miner_finds_known_flags():
     check(cands[0xa57]["reach_scenes"] >= 70, "0xa57 high scene reach")
     check(cands[0xa57]["category"] == "story-flag", "0xa57 classified story-flag")
 
+def test_bootstrap_is_additive_and_idempotent():
+    import tempfile, pathlib, story_flags
+    # start from a copy of the real toml so curated entries are present
+    src = (paths.VM_MAP / "globals.toml").read_text(encoding="utf-8")
+    with tempfile.TemporaryDirectory() as d:
+        tp = pathlib.Path(d) / "globals.toml"
+        tp.write_text(src, encoding="utf-8")
+        before, _ = G.load_toml(tp)
+        cands = story_flags.mine()
+        story_flags.bootstrap(cands, toml_path=tp)
+        after, _ = G.load_toml(tp)
+        check(len(after) > len(before), "bootstrap adds new skeleton entries")
+        check(after[0xa57]["name"] == "lily_form_a", "bootstrap preserves curated 0xa57")
+        # idempotent: second run adds nothing
+        n1 = len(after)
+        story_flags.bootstrap(story_flags.mine(), toml_path=tp)
+        after2, _ = G.load_toml(tp)
+        check(len(after2) == n1, "second bootstrap is a no-op (idempotent)")
+        # every skeleton is auto-shape and not high-confidence
+        added = set(after) - set(before)
+        check(all(after[a]["source"] == "auto-shape" for a in added), "skeletons are source=auto-shape")
+        check(all(after[a]["confidence"] != "high" for a in added), "skeletons never high confidence")
+
 if __name__ == "__main__":
     test_load_and_lint()
     test_lint_catches_bad_vocab()
     test_merge_precedence()
     test_sys4load_labels_from_registry()
     test_miner_finds_known_flags()
+    test_bootstrap_is_additive_and_idempotent()
     print(f"\n{len(FAILS)} failures")
     sys.exit(1 if FAILS else 0)