diff --git a/tests/test_toolsets.py b/tests/test_toolsets.py
index 4e4289999c..afd618a92e 100644
--- a/tests/test_toolsets.py
+++ b/tests/test_toolsets.py
@@ -32,6 +32,21 @@ class TestGetToolset:
         assert ts is not None
         assert "web_search" in ts["tools"]
 
+    def test_merges_registry_tools_into_builtin_toolset(self, monkeypatch):
+        reg = ToolRegistry()
+        reg.register(
+            name="web_search_plus",
+            toolset="web",
+            schema=_make_schema("web_search_plus", "Plugin web search"),
+            handler=_dummy_handler,
+        )
+
+        monkeypatch.setattr("tools.registry.registry", reg)
+
+        ts = get_toolset("web")
+        assert ts is not None
+        assert set(ts["tools"]) == {"web_search", "web_extract", "web_search_plus"}
+
     def test_unknown_returns_none(self):
         assert get_toolset("nonexistent") is None
 
diff --git a/toolsets.py b/toolsets.py
index 2a77f615ce..62ce91f8de 100644
--- a/toolsets.py
+++ b/toolsets.py
@@ -521,13 +521,18 @@ def get_toolset(name: str) -> Optional[Dict[str, Any]]:
         None: If toolset not found
     """
     toolset = TOOLSETS.get(name)
-    if toolset:
-        return toolset
 
     try:
         from tools.registry import registry
     except Exception:
-        return None
+        return toolset if toolset else None
+
+    if toolset:
+        merged_tools = sorted(
+            set(toolset.get("tools", []))
+            | set(registry.get_tool_names_for_toolset(name))
+        )
+        return {**toolset, "tools": merged_tools}
 
     registry_toolset = name
     description = f"Plugin toolset: {name}"