fix edge case casting and more test cases

tests/test_tool_validation.py

@@ -225,3 +225,139 @@ def test_cast_params_preserves_empty_string() -> None:
     )
     result = tool.cast_params({"name": ""})
     assert result["name"] == ""
+
+
+def test_cast_params_bool_string_false() -> None:
+    """Test that 'false', '0', 'no' strings convert to False."""
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {"flag": {"type": "boolean"}},
+        }
+    )
+    assert tool.cast_params({"flag": "false"})["flag"] is False
+    assert tool.cast_params({"flag": "False"})["flag"] is False
+    assert tool.cast_params({"flag": "0"})["flag"] is False
+    assert tool.cast_params({"flag": "no"})["flag"] is False
+    assert tool.cast_params({"flag": "NO"})["flag"] is False
+
+
+def test_cast_params_bool_string_invalid() -> None:
+    """Invalid boolean strings should not be cast."""
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {"flag": {"type": "boolean"}},
+        }
+    )
+    # Invalid strings should be preserved (validation will catch them)
+    result = tool.cast_params({"flag": "random"})
+    assert result["flag"] == "random"
+    result = tool.cast_params({"flag": "maybe"})
+    assert result["flag"] == "maybe"
+
+
+def test_cast_params_invalid_string_to_int() -> None:
+    """Invalid strings should not be cast to integer."""
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {"count": {"type": "integer"}},
+        }
+    )
+    result = tool.cast_params({"count": "abc"})
+    assert result["count"] == "abc"  # Original value preserved
+    result = tool.cast_params({"count": "12.5.7"})
+    assert result["count"] == "12.5.7"
+
+
+def test_cast_params_invalid_string_to_number() -> None:
+    """Invalid strings should not be cast to number."""
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {"rate": {"type": "number"}},
+        }
+    )
+    result = tool.cast_params({"rate": "not_a_number"})
+    assert result["rate"] == "not_a_number"
+
+
+def test_cast_params_none_values() -> None:
+    """Test None handling for different types."""
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {
+                "name": {"type": "string"},
+                "count": {"type": "integer"},
+                "items": {"type": "array"},
+                "config": {"type": "object"},
+            },
+        }
+    )
+    result = tool.cast_params(
+        {
+            "name": None,
+            "count": None,
+            "items": None,
+            "config": None,
+        }
+    )
+    # None should be preserved for all types
+    assert result["name"] is None
+    assert result["count"] is None
+    assert result["items"] is None
+    assert result["config"] is None
+
+
+def test_cast_params_single_value_not_auto_wrapped_to_array() -> None:
+    """Single values should NOT be automatically wrapped into arrays."""
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {"items": {"type": "array"}},
+        }
+    )
+    # Non-array values should be preserved (validation will catch them)
+    result = tool.cast_params({"items": 5})
+    assert result["items"] == 5  # Not wrapped to [5]
+    result = tool.cast_params({"items": "text"})
+    assert result["items"] == "text"  # Not wrapped to ["text"]
+
+
+def test_cast_params_empty_string_to_array() -> None:
+    """Empty string should convert to empty array."""
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {"items": {"type": "array"}},
+        }
+    )
+    result = tool.cast_params({"items": ""})
+    assert result["items"] == []
+
+
+def test_cast_params_empty_string_to_object() -> None:
+    """Empty string should convert to empty object."""
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {"config": {"type": "object"}},
+        }
+    )
+    result = tool.cast_params({"config": ""})
+    assert result["config"] == {}
+
+
+def test_cast_params_float_to_int() -> None:
+    """Float values should be cast to integers."""
+    tool = CastTestTool(
+        {
+            "type": "object",
+            "properties": {"count": {"type": "integer"}},
+        }
+    )
+    result = tool.cast_params({"count": 42.7})
+    assert result["count"] == 42
+    assert isinstance(result["count"], int)