diff --git a/tests/tools/test_delegate_composite_toolsets.py b/tests/tools/test_delegate_composite_toolsets.py
index fbb984ea4b..246d3aae6d 100644
--- a/tests/tools/test_delegate_composite_toolsets.py
+++ b/tests/tools/test_delegate_composite_toolsets.py
@@ -26,6 +26,14 @@ class TestExpandParentToolsets(unittest.TestCase):
         child_toolsets = [t for t in toolsets if t in expanded]
         self.assertEqual(child_toolsets, ["web"])
 
+    def test_included_toolsets_of_composite_parent_are_grantable(self):
+        """A composite parent holds its ``includes`` too (#111700): ``debugging`` = terminal/process_manage +
+        includes web/file, so a child may request ``web``/``file`` — but never a toolset the parent lacks."""
+        expanded = _expand_parent_toolsets({"debugging"})
+        self.assertTrue({"debugging", "terminal", "web", "file"} <= expanded)
+        self.assertNotIn("browser", expanded)
+        self.assertNotIn("hermes-cli", expanded)
+
     def test_composites_with_allowed_included_tools_are_not_stripped(self):
         toolsets = ["safe", "hermes-gateway", "hermes-cli", "delegation", "kanban"]
 
diff --git a/tools/delegate_tool_toolsets.py b/tools/delegate_tool_toolsets.py
index 0252dd9b65..ead1979a39 100644
--- a/tools/delegate_tool_toolsets.py
+++ b/tools/delegate_tool_toolsets.py
@@ -37,13 +37,19 @@ def _is_mcp_toolset_name(name: str) -> bool:
 
 def _expand_parent_toolsets(parent_toolsets: set) -> set:
     """Add every toolset whose tools are a subset of the parent's tools: a parent on a composite like ``hermes-cli``
-    must still let a child request ``web``/``terminal``; bare name intersection would reject them."""
-    parent_tool_names = {t for ts_name in parent_toolsets for t in (TOOLSETS.get(ts_name) or {}).get("tools", [])}
+    must still let a child request ``web``/``terminal``; bare name intersection would reject them. Both sides use
+    the RESOLVED static surface: a composite's ``includes`` (``debugging`` -> ``web``/``file``, ``safe``) are tools
+    the parent genuinely holds, and the child never gains a tool the parent lacks."""
+    parent_tool_names = {
+        t for ts_name in parent_toolsets if ts_name in TOOLSETS for t in resolve_toolset(ts_name, include_registry=False)
+    }
     expanded = set(parent_toolsets)
     if parent_tool_names:
         expanded.update(
-            ts_name for ts_name, ts_def in TOOLSETS.items()
-            if ts_name not in expanded and ts_def.get("tools") and set(ts_def["tools"]).issubset(parent_tool_names)
+            ts_name for ts_name in TOOLSETS
+            if ts_name not in expanded
+            and (resolved := resolve_toolset(ts_name, include_registry=False))
+            and set(resolved).issubset(parent_tool_names)
         )
     return expanded