diff --git a/aider/tools/context_manager.py b/aider/tools/context_manager.py
index 740b91ed785..e8cd5956fc3 100644
--- a/aider/tools/context_manager.py
+++ b/aider/tools/context_manager.py
@@ -67,10 +67,37 @@ def execute(cls, coder, remove=None, editable=None, view=None, create=None):
         create: list[str] | None
             Files to create and make editable.
         """
-        remove_files = remove or []
-        editable_files = editable or []
-        view_files = view or []
-        create_files = create or []
+
+        # Helper to parse string arguments that might be JSON arrays
+        def parse_arg(arg):
+            if arg is None:
+                return []
+            if isinstance(arg, list):
+                return arg
+            if isinstance(arg, str):
+                # Handle empty or whitespace-only string as empty list
+                if not arg or arg.isspace():
+                    return []
+                # Try to parse as JSON array
+                import json
+
+                try:
+                    parsed = json.loads(arg)
+                    if isinstance(parsed, list):
+                        return parsed
+                    else:
+                        # If it's not a list, wrap it in a list
+                        return [parsed]
+                except json.JSONDecodeError:
+                    # If not valid JSON, treat as a single file path
+                    return [arg]
+            # For any other type, wrap in list
+            return [arg]
+
+        remove_files = parse_arg(remove)
+        editable_files = parse_arg(editable)
+        view_files = parse_arg(view)
+        create_files = parse_arg(create)
 
         if not remove_files and not editable_files and not view_files and not create_files:
             raise ToolError("You must specify at least one of: remove, editable, view, or create")
diff --git a/tests/tools/test_context_manager.py b/tests/tools/test_context_manager.py
new file mode 100644
index 00000000000..73867e4625d
--- /dev/null
+++ b/tests/tools/test_context_manager.py
@@ -0,0 +1,144 @@
+"""Tests for the ContextManager tool."""
+
+from unittest.mock import Mock
+
+import pytest
+
+from aider.tools.context_manager import Tool as ContextManagerTool
+from aider.tools.utils.helpers import ToolError
+
+
+class TestContextManagerTool:
+    """Test suite for ContextManager tool."""
+
+    def setup_method(self):
+        """Set up a mock coder for each test."""
+        self.coder = Mock()
+        self.coder.abs_root_path = Mock(side_effect=lambda x: x)
+        self.coder.get_rel_fname = Mock(side_effect=lambda x: x)
+        self.coder.abs_fnames = set()
+        self.coder.abs_read_only_fnames = set()
+        self.coder.recently_removed = {}
+        self.coder.io = Mock()
+        self.coder.io.tool_output = Mock()
+        self.coder.io.tool_error = Mock()
+        self.coder._add_file_to_context = Mock(return_value="Viewed: test.py")
+
+    def test_execute_with_valid_lists(self):
+        """Test execute with proper list arguments."""
+        result = ContextManagerTool.execute(
+            self.coder,
+            remove=["file1.py"],
+            editable=["file2.py"],
+            view=["file3.py"],
+            create=["file4.py"],
+        )
+        assert "Removed: file1.py" in result
+        assert "Made editable" in result
+        assert "Viewed: test.py" in result
+        assert "Created and made editable: file4.py" in result
+
+    def test_execute_with_json_string_arrays(self):
+        """Test execute with JSON string arrays that should be parsed."""
+        # Simulate the LLM generating a JSON string for the view argument
+        view_json = '["file1.py", "file2.py"]'
+        ContextManagerTool.execute(self.coder, view=view_json)
+        # The tool should parse the JSON string and treat it as a list
+        # Since we mock _add_file_to_context to return "Viewed: test.py",
+        # we need to check it was called twice
+        assert self.coder._add_file_to_context.call_count == 2
+        calls = self.coder._add_file_to_context.call_args_list
+        assert calls[0][0][0] == "file1.py"
+        assert calls[1][0][0] == "file2.py"
+
+    def test_execute_with_empty_string(self):
+        """Test execute with empty string argument."""
+        # Empty string should be treated as empty list
+        with pytest.raises(ToolError):
+            ContextManagerTool.execute(self.coder, view="")
+
+    def test_execute_with_malformed_json_string(self):
+        """Test execute with a malformed JSON string that should be treated as a single file."""
+        # A string that is not valid JSON should be treated as a single file path
+        view_string = "file1.py"
+        ContextManagerTool.execute(self.coder, view=view_string)
+        self.coder._add_file_to_context.assert_called_once_with("file1.py", explicit=True)
+
+    def test_execute_with_whitespace_string(self):
+        """Test execute with whitespace-only string argument."""
+        # Whitespace-only string should be treated as empty list
+        with pytest.raises(ToolError):
+            ContextManagerTool.execute(self.coder, view="   ")
+        with pytest.raises(ToolError):
+            ContextManagerTool.execute(self.coder, view="\t\n")
+
+    def test_execute_with_single_json_string_element(self):
+        """Test execute with a JSON string representing a single element (not array)."""
+        # JSON string that is a single string (not array) should be wrapped in a list
+        view_json = '"file1.py"'
+        ContextManagerTool.execute(self.coder, view=view_json)
+        self.coder._add_file_to_context.assert_called_once_with("file1.py", explicit=True)
+
+    def test_execute_with_none_arguments(self):
+        """Test execute with None arguments."""
+        # Should raise ToolError because no operations specified
+        with pytest.raises(ToolError):
+            ContextManagerTool.execute(self.coder)
+
+    def test_execute_with_empty_lists(self):
+        """Test execute with empty lists."""
+        with pytest.raises(ToolError):
+            ContextManagerTool.execute(self.coder, remove=[], view=[])
+
+    def test_parse_arg_helper(self):
+        """Test the parse_arg behavior through execute method."""
+        # Test with None
+        with pytest.raises(ToolError):
+            ContextManagerTool.execute(self.coder, view=None)
+
+        # Test with list
+        self.coder._add_file_to_context.reset_mock()
+        ContextManagerTool.execute(self.coder, view=["test1.py", "test2.py"])
+        assert self.coder._add_file_to_context.call_count == 2
+
+        # Test with JSON string array
+        self.coder._add_file_to_context.reset_mock()
+        ContextManagerTool.execute(self.coder, view='["test1.py", "test2.py"]')
+        assert self.coder._add_file_to_context.call_count == 2
+
+        # Test with non-JSON string
+        self.coder._add_file_to_context.reset_mock()
+        ContextManagerTool.execute(self.coder, view="test1.py")
+        self.coder._add_file_to_context.assert_called_once_with("test1.py", explicit=True)
+
+        # Test with JSON string that's not an array
+        self.coder._add_file_to_context.reset_mock()
+        ContextManagerTool.execute(self.coder, view='"test1.py"')
+        self.coder._add_file_to_context.assert_called_once_with("test1.py", explicit=True)
+
+    def test_error_handling(self):
+        """Test that errors are properly propagated."""
+        self.coder._add_file_to_context.side_effect = Exception("Test error")
+        result = ContextManagerTool.execute(self.coder, view=["test.py"])
+        assert "Error viewing" in result
+        self.coder.io.tool_error.assert_called()
+
+    def test_json_string_with_escaped_quotes(self):
+        """Test the specific case from the bug report: JSON string with escaped quotes."""
+        # This simulates the exact tool call that caused the error:
+        # {"view": "[\"aider/coders/base_coder.py\"]"}
+        view_json = '["aider/coders/base_coder.py"]'
+        ContextManagerTool.execute(self.coder, view=view_json)
+        # Should parse as a single file, not as individual characters
+        self.coder._add_file_to_context.assert_called_once_with(
+            "aider/coders/base_coder.py", explicit=True
+        )
+
+        # Also test with multiple files
+        self.coder._add_file_to_context.reset_mock()
+        view_json = '["file1.py", "file2.py"]'
+        ContextManagerTool.execute(self.coder, view=view_json)
+        assert self.coder._add_file_to_context.call_count == 2
+        calls = self.coder._add_file_to_context.call_args_list
+        assert calls[0][0][0] == "file1.py"
+        assert calls[1][0][0] == "file2.py"