Add patch debugging guide and analysis

- Created comprehensive debugging guide for patch failures
- Identified common issues: modified context, not found, formatting
- Documented solutions and best practices
- Added example of robust patching approach
- Note: The reported patch failure was because the content was already added

Author: Your Name

patch_debugging_guide.md

@@ -0,0 +1,95 @@
+# Why MCP File Edit Patches Fail - Common Issues and Solutions
+
+## 1. Context Already Modified
+**Issue**: The context you're looking for has already been changed by a previous edit.
+**Solution**: Check the current file content first, or use a more unique context.
+
+## 2. Context Not Found
+**Issue**: The exact lines specified in context don't exist as continuous lines.
+**Common Causes**:
+- Extra or missing whitespace
+- Different line endings
+- Content has moved
+- Partial match only
+
+**Solutions**:
+- Use `read_file` to check exact content first
+- Use more specific, unique context
+- Use line-based patches if you know the exact line numbers
+
+## 3. Markdown Formatting Issues
+**Issue**: Incorrect number of backticks in code blocks (e.g., 4 instead of 3)
+**Solution**: Ensure markdown syntax is correct: ` ``` ` not ` ```` `
+
+## 4. Multiple Matches
+**Issue**: Context appears multiple times in the file
+**Solution**: 
+- Use more lines of context for uniqueness
+- Specify `occurrence` parameter (1-based)
+- Use pattern-based patches with `occurrence`
+
+## 5. Special Characters
+**Issue**: Regex special characters in find/replace patterns
+**Solution**: 
+- Escape special characters: `(`, `)`, `[`, `]`, etc.
+- Use `regex: false` for literal matching (if supported)
+
+## Debugging Tips
+
+1. **Always check current content first**:
+   ```python
+   content = read_file("myfile.txt")
+   # Verify your context exists
+   ```
+
+2. **Use specific context**:
+   ```python
+   # Bad - too generic
+   {"context": ["", "## Tools"]}
+   
+   # Good - more specific
+   {"context": ["specific line", "", "## Tools"]}
+   ```
+
+3. **Use line numbers when possible**:
+   ```python
+   # If you know the exact line
+   {"line": 42, "content": "new content"}
+   ```
+
+4. **Test with dry_run**:
+   ```python
+   patch_file("file.txt", patches=[...], dry_run=True)
+   ```
+
+## Enhanced Error Messages
+
+The improved patch function now provides:
+- Exact search details
+- Partial match locations
+- Specific mismatch information
+- Suggestions for fixes
+
+## Example: Robust Patching
+
+```python
+# First, check what's there
+content = read_file("config.py")
+
+# Find unique context
+search_results = search_files("specific_string", "config.py")
+
+# Use robust context
+patch_file("config.py", patches=[{
+    "context": [
+        "# Unique comment",
+        "def my_function():",
+        "    return old_value"
+    ],
+    "replace": [
+        "# Unique comment", 
+        "def my_function():",
+        "    return new_value"
+    ]
+}])
+```