diff --git a/aider/coders/navigator_coder.py b/aider/coders/navigator_coder.py
index 866ad6ca5..d3f2fb994 100644
--- a/aider/coders/navigator_coder.py
+++ b/aider/coders/navigator_coder.py
@@ -1,3 +1,4 @@
+import ast
 import re
 import fnmatch
 import os
@@ -350,66 +351,149 @@ class NavigatorCoder(Coder):
         call_count = 0
         max_calls = self.max_tool_calls
 
-        # Regex to find tool calls: [tool_call(name, key=value, key="value", ...)]
-        # It captures the tool name and the arguments string.
-        # It handles quoted and unquoted values.
-        tool_call_pattern = re.compile(
-            r"\[tool_call\(\s*([a-zA-Z_][a-zA-Z0-9_]*)\s*" # Tool name
-            r"(?:,\s*(.*?))?\s*\)\]" # Optional arguments string (non-greedy)
-        )
+        # Find tool calls using a more robust method
+        processed_content = ""
+        last_index = 0
+        start_marker = "[tool_call("
+        end_marker = "]" # The parenthesis balancing finds the ')', we just need the final ']'
 
-        # Regex to parse key=value pairs within the arguments string
-        # Handles key=value, key="value", key='value'
-        # Allows values to contain commas if quoted
-        args_pattern = re.compile(
-            r"([a-zA-Z_][a-zA-Z0-9_]*)\s*=\s*" # Key
-            r"(?:\"(.*?)\"|\'(.*?)\'|([^,\s\'\"]*))" # Value (quoted or unquoted)
-        )
+        while True:
+            start_pos = content.find(start_marker, last_index)
+            if start_pos == -1:
+                processed_content += content[last_index:]
+                break
 
-        processed_indices = set() # Keep track of processed match ranges
+            # Append content before the tool call
+            processed_content += content[last_index:start_pos]
 
-        for match in tool_call_pattern.finditer(content):
-            # Skip overlapping matches if a previous match already covered this area
-            if any(match.start() >= start and match.end() <= end for start, end in processed_indices):
+            scan_start_pos = start_pos + len(start_marker)
+            paren_level = 1
+            in_single_quotes = False
+            in_double_quotes = False
+            escaped = False
+            end_paren_pos = -1
+
+            # Scan to find the matching closing parenthesis, respecting quotes
+            for i in range(scan_start_pos, len(content)):
+                char = content[i]
+
+                if escaped:
+                    escaped = False
+                elif char == '\\':
+                    escaped = True
+                elif char == "'" and not in_double_quotes:
+                    in_single_quotes = not in_single_quotes
+                elif char == '"' and not in_single_quotes:
+                    in_double_quotes = not in_double_quotes
+                elif char == '(' and not in_single_quotes and not in_double_quotes:
+                    paren_level += 1
+                elif char == ')' and not in_single_quotes and not in_double_quotes:
+                    paren_level -= 1
+                    if paren_level == 0:
+                        end_paren_pos = i
+                        break
+
+            # Check for the end marker after the closing parenthesis, skipping whitespace
+            expected_end_marker_start = end_paren_pos + 1
+            actual_end_marker_start = -1
+            end_marker_found = False
+            if end_paren_pos != -1: # Only search if we found a closing parenthesis
+                for j in range(expected_end_marker_start, len(content)):
+                    if not content[j].isspace():
+                        actual_end_marker_start = j
+                        # Check if the found character is the end marker ']'
+                        if content[actual_end_marker_start] == end_marker:
+                            end_marker_found = True
+                        break # Stop searching after first non-whitespace char
+
+            if not end_marker_found:
+                # Malformed call: couldn't find matching ')' or the subsequent ']'
+                self.io.tool_warning(f"Malformed tool call starting at index {start_pos}. Skipping (end_paren_pos={end_paren_pos}, end_marker_found={end_marker_found}).")
+                # Append the start marker itself to processed content so it's not lost
+                processed_content += start_marker
+                last_index = scan_start_pos # Continue searching after the marker
                 continue
 
+            # Found a potential tool call
+            # Adjust full_match_str and last_index based on the actual end marker ']' position
+            full_match_str = content[start_pos : actual_end_marker_start + 1] # End marker ']' is 1 char
+            inner_content = content[scan_start_pos:end_paren_pos].strip()
+            last_index = actual_end_marker_start + 1 # Move past the processed call (including ']')
+
+
             call_count += 1
             if call_count > max_calls:
                 self.io.tool_warning(f"Exceeded maximum tool calls ({max_calls}). Skipping remaining calls.")
-                break
+                # Don't append the skipped call to processed_content
+                continue # Skip processing this call
 
-            tool_name = match.group(1)
-            args_str = match.group(2) or ""
-            full_match_str = match.group(0)
-
-            # We no longer need to handle Continue separately, as we'll continue if any tool calls exist
-            # Just track that a tool call was found
             tool_calls_found = True
-
-            # Extract parameters
+            tool_name = None
             params = {}
-            suppressed_arg_values = ["..."] # Values to ignore during parsing
+            result_message = None
+
             try:
-                for arg_match in args_pattern.finditer(args_str):
-                    key = arg_match.group(1)
-                    # Value can be in group 2 (double quotes), 3 (single quotes), or 4 (unquoted)
-                    value = arg_match.group(2) or arg_match.group(3) or arg_match.group(4)
+                # Wrap the inner content to make it parseable as a function call
+                # Example: ToolName, key="value" becomes f(ToolName, key="value")
+                parse_str = f"f({inner_content})"
+                parsed_ast = ast.parse(parse_str)
 
-                    # Check if the value is suppressed
-                    if value in suppressed_arg_values:
+                # Validate AST structure
+                if not isinstance(parsed_ast, ast.Module) or not parsed_ast.body or not isinstance(parsed_ast.body[0], ast.Expr):
+                    raise ValueError("Unexpected AST structure")
+                call_node = parsed_ast.body[0].value
+                if not isinstance(call_node, ast.Call):
+                     raise ValueError("Expected a Call node")
+
+                # Extract tool name (should be the first positional argument)
+                if not call_node.args or not isinstance(call_node.args[0], ast.Name):
+                    raise ValueError("Tool name not found or invalid")
+                tool_name = call_node.args[0].id
+
+                # Extract keyword arguments
+                for keyword in call_node.keywords:
+                    key = keyword.arg
+                    value_node = keyword.value
+                    # Extract value based on AST node type
+                    if isinstance(value_node, ast.Constant):
+                        value = value_node.value
+                    elif isinstance(value_node, ast.Name): # Handle unquoted values like True/False/None or variables (though variables are unlikely here)
+                        value = value_node.id
+                    # Add more types if needed (e.g., ast.List, ast.Dict)
+                    else:
+                        # Attempt to reconstruct the source for complex types, or raise error
+                        try:
+                            # Note: ast.unparse requires Python 3.9+
+                            # If using older Python, might need a different approach or limit supported types
+                            value = ast.unparse(value_node)
+                        except AttributeError: # Handle case where ast.unparse is not available
+                             raise ValueError(f"Unsupported argument type for key '{key}': {type(value_node)}")
+                        except Exception as ue:
+                             raise ValueError(f"Could not unparse value for key '{key}': {ue}")
+
+
+                    # Check for suppressed values (e.g., "...")
+                    suppressed_arg_values = ["..."]
+                    if isinstance(value, str) and value in suppressed_arg_values:
                         self.io.tool_warning(f"Skipping suppressed argument value '{value}' for key '{key}' in tool '{tool_name}'")
-                        continue # Skip this argument
+                        continue
 
-                    params[key] = value if value is not None else ""
-            except Exception as e:
-                 result_messages.append(f"[Result ({tool_name}): Error parsing arguments '{args_str}': {e}]")
-                 # Remove the malformed call from the content
-                 modified_content = modified_content.replace(full_match_str, "", 1)
-                 processed_indices.add((match.start(), match.end()))
-                 continue # Skip execution if args parsing failed
+                    params[key] = value
+
+
+            except (SyntaxError, ValueError) as e:
+                result_message = f"Error parsing tool call '{inner_content}': {e}"
+                self.io.tool_error(f"Failed to parse tool call: {full_match_str}\nError: {e}")
+                # Don't append the malformed call to processed_content
+                result_messages.append(f"[Result (Parse Error): {result_message}]")
+                continue # Skip execution
+            except Exception as e: # Catch any other unexpected parsing errors
+                result_message = f"Unexpected error parsing tool call '{inner_content}': {e}"
+                self.io.tool_error(f"Unexpected error during parsing: {full_match_str}\nError: {e}\n{traceback.format_exc()}")
+                result_messages.append(f"[Result (Parse Error): {result_message}]")
+                continue
 
             # Execute the tool based on its name
-            result_message = None
             try:
                 # Normalize tool name for case-insensitive matching
                 norm_tool_name = tool_name.lower()
@@ -474,14 +558,18 @@ class NavigatorCoder(Coder):
 
             except Exception as e:
                 result_message = f"Error executing {tool_name}: {str(e)}"
-                self.io.tool_error(f"Error during {tool_name} execution: {e}")
+                self.io.tool_error(f"Error during {tool_name} execution: {e}\n{traceback.format_exc()}")
 
             if result_message:
                 result_messages.append(f"[Result ({tool_name}): {result_message}]")
 
-            # Remove the processed tool call from the content
-            modified_content = modified_content.replace(full_match_str, "", 1)
-            processed_indices.add((match.start(), match.end()))
+            # Note: We don't add the tool call string back to processed_content
+
+        # Update internal counter
+        self.tool_call_count += call_count
+
+        # Return the content with tool calls removed
+        modified_content = processed_content
 
         # Update internal counter
         self.tool_call_count += call_count