diff --git a/superset/mcp_service/sql_lab/schemas.py b/superset/mcp_service/sql_lab/schemas.py
index f7c25266fdb..729413a9d53 100644
--- a/superset/mcp_service/sql_lab/schemas.py
+++ b/superset/mcp_service/sql_lab/schemas.py
@@ -191,6 +191,14 @@ class ExecuteSqlResponse(BaseModel):
             "Check each entry in the statements array for per-statement data."
         ),
     )
+    template_warning: str | None = Field(
+        None,
+        description=(
+            "Warning when template_params was supplied but Jinja2 rendering "
+            "is disabled on this Superset instance. The query was executed "
+            "with literal '{{ var }}' placeholders unrendered."
+        ),
+    )
 
 
 class SaveSqlQueryRequest(BaseModel):
diff --git a/superset/mcp_service/sql_lab/tool/execute_sql.py b/superset/mcp_service/sql_lab/tool/execute_sql.py
index 45043a068f5..c1000320a4d 100644
--- a/superset/mcp_service/sql_lab/tool/execute_sql.py
+++ b/superset/mcp_service/sql_lab/tool/execute_sql.py
@@ -86,7 +86,7 @@ async def execute_sql(request: ExecuteSqlRequest, ctx: Context) -> ExecuteSqlRes
 
     try:
         # Import inside function to avoid initialization issues
-        from superset import db, security_manager
+        from superset import db, is_feature_enabled, security_manager
         from superset.models.core import Database
 
         # 1. Get database and check access
@@ -134,6 +134,22 @@ async def execute_sql(request: ExecuteSqlRequest, ctx: Context) -> ExecuteSqlRes
         with event_logger.log_context(action="mcp.execute_sql.response_conversion"):
             response = _convert_to_response(result)
 
+        # Surface a warning when template_params is supplied but Jinja
+        # rendering is disabled — otherwise the params are silently dropped.
+        if request.template_params and not is_feature_enabled(
+            "ENABLE_TEMPLATE_PROCESSING"
+        ):
+            response.template_warning = (
+                "template_params was supplied but Jinja2 rendering is "
+                "disabled on this Superset instance "
+                "(ENABLE_TEMPLATE_PROCESSING feature flag is off). "
+                "Template variables in the SQL were NOT substituted; "
+                "the query was executed with literal '{{ var }}' placeholders."
+            )
+            await ctx.warning(
+                "template_params supplied but ENABLE_TEMPLATE_PROCESSING is off"
+            )
+
         # Log successful execution
         if response.success:
             await ctx.info(
diff --git a/tests/unit_tests/mcp_service/sql_lab/tool/test_execute_sql.py b/tests/unit_tests/mcp_service/sql_lab/tool/test_execute_sql.py
index e1d3dee8e39..de67736ac55 100644
--- a/tests/unit_tests/mcp_service/sql_lab/tool/test_execute_sql.py
+++ b/tests/unit_tests/mcp_service/sql_lab/tool/test_execute_sql.py
@@ -229,6 +229,105 @@ class TestExecuteSql:
             assert "{{ table }}" in data["statements"][0]["original_sql"]
             assert "orders" in data["statements"][0]["executed_sql"]
 
+    @patch("superset.is_feature_enabled")
+    @patch("superset.security_manager")
+    @patch("superset.db")
+    @pytest.mark.asyncio
+    async def test_template_warning_when_flag_disabled(
+        self, mock_db, mock_security_manager, mock_is_feature_enabled, mcp_server
+    ):
+        """Warn when template_params is set but ENABLE_TEMPLATE_PROCESSING is off."""
+        mock_database = _mock_database()
+        mock_database.execute.return_value = _create_select_result(
+            rows=[],
+            columns=["id"],
+            original_sql="SELECT * FROM users WHERE id = '{{ user_id }}'",
+            executed_sql="SELECT * FROM users WHERE id = '{{ user_id }}'",
+        )
+        mock_db.session.query.return_value.filter_by.return_value.first.return_value = (
+            mock_database
+        )
+        mock_security_manager.can_access_database.return_value = True
+        mock_is_feature_enabled.return_value = False
+
+        request = {
+            "database_id": 1,
+            "sql": "SELECT * FROM users WHERE id = '{{ user_id }}'",
+            "template_params": {"user_id": "42"},
+        }
+
+        async with Client(mcp_server) as client:
+            result = await client.call_tool("execute_sql", {"request": request})
+            data = result.structured_content
+
+            assert data["success"] is True
+            assert data["template_warning"] is not None
+            assert "ENABLE_TEMPLATE_PROCESSING" in data["template_warning"]
+            mock_is_feature_enabled.assert_called_with("ENABLE_TEMPLATE_PROCESSING")
+
+    @patch("superset.is_feature_enabled")
+    @patch("superset.security_manager")
+    @patch("superset.db")
+    @pytest.mark.asyncio
+    async def test_no_template_warning_when_flag_enabled(
+        self, mock_db, mock_security_manager, mock_is_feature_enabled, mcp_server
+    ):
+        """No warning when ENABLE_TEMPLATE_PROCESSING is on."""
+        mock_database = _mock_database()
+        mock_database.execute.return_value = _create_select_result(
+            rows=[{"id": 42}],
+            columns=["id"],
+            original_sql="SELECT * FROM users WHERE id = '42'",
+            executed_sql="SELECT * FROM users WHERE id = '42'",
+        )
+        mock_db.session.query.return_value.filter_by.return_value.first.return_value = (
+            mock_database
+        )
+        mock_security_manager.can_access_database.return_value = True
+        mock_is_feature_enabled.return_value = True
+
+        request = {
+            "database_id": 1,
+            "sql": "SELECT * FROM users WHERE id = '{{ user_id }}'",
+            "template_params": {"user_id": "42"},
+        }
+
+        async with Client(mcp_server) as client:
+            result = await client.call_tool("execute_sql", {"request": request})
+            data = result.structured_content
+
+            assert data["success"] is True
+            assert data["template_warning"] is None
+
+    @patch("superset.is_feature_enabled")
+    @patch("superset.security_manager")
+    @patch("superset.db")
+    @pytest.mark.asyncio
+    async def test_no_template_warning_without_template_params(
+        self, mock_db, mock_security_manager, mock_is_feature_enabled, mcp_server
+    ):
+        """No warning when template_params is not supplied, even with flag off."""
+        mock_database = _mock_database()
+        mock_database.execute.return_value = _create_select_result(
+            rows=[{"id": 1}],
+            columns=["id"],
+        )
+        mock_db.session.query.return_value.filter_by.return_value.first.return_value = (
+            mock_database
+        )
+        mock_security_manager.can_access_database.return_value = True
+        mock_is_feature_enabled.return_value = False
+
+        request = {"database_id": 1, "sql": "SELECT id FROM users"}
+
+        async with Client(mcp_server) as client:
+            result = await client.call_tool("execute_sql", {"request": request})
+            data = result.structured_content
+
+            assert data["success"] is True
+            assert data["template_warning"] is None
+            mock_is_feature_enabled.assert_not_called()
+
     @patch("superset.security_manager")
     @patch("superset.db")
     @pytest.mark.asyncio