Problem

The multi_replace_string_tool and replace_string_tool currently fail when attempting to replace a string that appears multiple times in a file, throwing an unhelpful error:

String replacement failed: Multiple matches found for the text to replace. 
Multiple exact matches found. Make your search string more specific.

This creates friction when users need to make repetitive changes across a file, forcing them to either make the search string more specific or perform multiple separate replacements.

Solution

This PR adds an optional replaceAll parameter to the IReplaceStringToolParams interface that allows replacing all occurrences of a string instead of failing when multiple matches are found.

Key Changes

Enhanced Interface

export interface IReplaceStringToolParams {
  explanation: string;
  filePath: string;
  oldString: string;
  newString: string;
  replaceAll?: boolean;  // New optional parameter
}

Improved Error Messages
When multiple matches are found and replaceAll is not set, the tool now provides actionable guidance:

Multiple exact matches found on lines 1, 2, 4. Make your search string more specific or use replaceAll: true to replace all occurrences.

Robust Implementation

• Supports all matching strategies (exact, fuzzy, whitespace-flexible)
• Replaces occurrences from right to left to avoid position shift issues
• Maintains 100% backward compatibility - existing code works unchanged
• Includes comprehensive test coverage for edge cases

Usage Example

// Before: This would fail with multiple matches error
{
  filePath: '/src/utils.ts',
  oldString: 'console.log',
  newString: 'logger.info'
}

// After: This replaces all occurrences
{
  filePath: '/src/utils.ts', 
  oldString: 'console.log',
  newString: 'logger.info',
  replaceAll: true
}

Benefits

• Reduces friction when making repetitive changes across files
• Provides actionable guidance with specific line numbers instead of generic error messages
• Maintains backward compatibility - no breaking changes to existing functionality
• Supports all matching strategies including fuzzy and whitespace-flexible matching
• Clean implementation with comprehensive test coverage and security validation

This enhancement makes the string replacement tools significantly more user-friendly while maintaining their robustness and reliability.

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