@@ -641,7 +641,8 @@ def __init__(
 
         if not self.valid_scale_and_precision():
             raise ValueError(
-                "DecimalParameter requires both or none of scale and precision to be set"
+                "DecimalParameter requires both or none of scale and precision to be set, "
+                "as integers"
             )
 
         if self.scale is not None and self.precision is not None and self.scale > self.precision:
@@ -677,8 +678,13 @@ def __init__(
                 )
 
     def valid_scale_and_precision(self):
+        def _is_int(x):
+            # bool is a subclass of int; reject it so precision=True/scale=False
+            # cannot silently bind DECIMAL(1,0).
+            return isinstance(x, int) and not isinstance(x, bool)
+
         if (self.scale is None and self.precision is None) or (
-            isinstance(self.scale, int) and isinstance(self.precision, int)
+            _is_int(self.scale) and _is_int(self.precision)
         ):
             return True
         else:
@@ -687,7 +693,20 @@ def valid_scale_and_precision(self):
     def _cast_expr(self):
         if self.scale is not None and self.precision is not None:
             precision, scale = self._effective_precision_and_scale(self.precision, self.scale)
-            if (precision, scale) != (self.precision, self.scale):
+            if precision - scale > self.precision - self.scale:
+                # The value has more integer digits than the declared type allows.
+                # Earlier releases let the server reject this as out of range, so
+                # surface it above DEBUG for callers relying on the declared type.
+                logger.warning(
+                    "DecimalParameter value has more integer digits than declared "
+                    "DECIMAL(%d,%d) allows; it is bound as DECIMAL(%d,%d) instead of "
+                    "being rejected as out of range",
+                    self.precision,
+                    self.scale,
+                    precision,
+                    scale,
+                )
+            elif (precision, scale) != (self.precision, self.scale):
                 logger.debug(
                     "DecimalParameter declared DECIMAL(%d,%d) is bound as DECIMAL(%d,%d) "
                     "to fit the value's digits (precision capped at 38)",
 
@@ -153,6 +153,24 @@ def test_decimal_widened_type_is_logged(caplog):
     assert "DECIMAL(10,2) is bound as DECIMAL(12,4)" in caplog.text
 
 
+def test_decimal_widened_integer_room_is_warned(caplog):
+    """Widening the integer room (no longer an out-of-range error) is logged at WARNING."""
+    p = DecimalParameter(Decimal("123456789012.5"), scale=2, precision=10)
+    with caplog.at_level("WARNING", logger="databricks.sql.parameters.native"):
+        assert p._cast_expr() == "DECIMAL(14,2)"
+    warnings = [r for r in caplog.records if r.levelname == "WARNING"]
+    assert len(warnings) == 1
+    assert "DECIMAL(10,2) allows; it is bound as DECIMAL(14,2)" in warnings[0].getMessage()
+
+
+def test_decimal_widened_scale_only_is_not_warned(caplog):
+    """Scale-only widening (the bug fix) stays at DEBUG, not WARNING."""
+    p = DecimalParameter(Decimal("123.4567"), scale=2, precision=10)
+    with caplog.at_level("DEBUG", logger="databricks.sql.parameters.native"):
+        assert p._cast_expr() == "DECIMAL(12,4)"
+    assert not [r for r in caplog.records if r.levelname == "WARNING"]
+
+
 def test_decimal_unchanged_type_is_not_logged(caplog):
     p = DecimalParameter(Decimal("123.45"), scale=2, precision=10)
     with caplog.at_level("DEBUG", logger="databricks.sql.parameters.native"):
@@ -182,6 +200,16 @@ def test_decimal_invalid_declared_precision_or_scale_raises(scale, precision, ma
         DecimalParameter(Decimal("1.5"), scale=scale, precision=precision)
 
 
+@pytest.mark.parametrize(
+    "scale,precision",
+    ((False, True), (0, True), (False, 10)),
+)
+def test_decimal_bool_scale_or_precision_raises(scale, precision):
+    """bool is an int subclass but must not be accepted as a scale/precision."""
+    with pytest.raises(ValueError, match="as integers"):
+        DecimalParameter(Decimal("1.5"), scale=scale, precision=precision)
+
+
 def test_decimal_legacy_swapped_out_of_range_precision_raises():
     """The range check applies after the legacy swap (scale=50 becomes precision=50)."""
     with pytest.warns(FutureWarning, match="legacy"):