fix(mcp): preserve compact chart config schema guidance

superset/mcp_service/chart/schemas.py

@@ -1271,6 +1271,10 @@ _CHART_CONFIG_DESCRIPTION = (
     "'pivot_table' (rows, metrics), 'mixed_timeseries' (x, y, y_secondary), "
     "'handlebars' (columns, handlebars_template), "
     "'big_number' (metric). "
+    "Do not use Superset Explore form-data fields like 'viz_type' or "
+    "'time_range', and do not use Superset viz type names like "
+    "'echarts_timeseries_bar' as chart_type. For bar charts use "
+    "{'chart_type': 'xy', 'kind': 'bar', ...}. "
     "See chart://configs resource for full field reference and examples."
 )
 

tests/unit_tests/mcp_service/chart/test_chart_schemas.py

@@ -23,6 +23,7 @@ import pytest
 from pydantic import ValidationError
 
 from superset.mcp_service.chart.schemas import (
+    _CHART_CONFIG_DESCRIPTION,
     ColumnRef,
     GenerateChartRequest,
     parse_chart_config,
@@ -31,6 +32,16 @@ from superset.mcp_service.chart.schemas import (
 )
 
 
+def test_chart_config_description_warns_against_form_data_fields() -> None:
+    """Compact tool schema points LLMs to the MCP chart config dialect."""
+    assert "'chart_type': 'xy'" in _CHART_CONFIG_DESCRIPTION
+    assert "'kind': 'bar'" in _CHART_CONFIG_DESCRIPTION
+    assert "Superset Explore form-data" in _CHART_CONFIG_DESCRIPTION
+    assert "viz_type" in _CHART_CONFIG_DESCRIPTION
+    assert "time_range" in _CHART_CONFIG_DESCRIPTION
+    assert "echarts_timeseries_bar" in _CHART_CONFIG_DESCRIPTION
+
+
 class TestTableChartConfig:
     """Test TableChartConfig validation."""