docs: Add PR description file for issue #5496

Author: roomote

pr_description.md

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+## Description
+
+Fixes #5496
+
+This PR enhances the ToolRepetitionDetector to detect non-continuous repetitive tool call patterns (e.g., ABABAB) to prevent the AI from getting stuck in alternating tool call loops.
+
+## Changes Made
+
+- **Enhanced ToolRepetitionDetector**: Added pattern detection algorithm that identifies repeating sequences of tool calls beyond just consecutive repetitions
+- **Pattern Detection Algorithm**: Implements detection for patterns of length 2-6 with configurable minimum repetitions (default: 2)
+- **History Tracking**: Maintains a rolling history of the last 20 tool calls for pattern analysis
+- **Backward Compatibility**: Preserves existing consecutive repetition detection behavior
+- **Comprehensive Testing**: Added 15+ new test cases covering various pattern scenarios
+
+## Technical Implementation
+
+### Key Features:
+
+- Detects patterns like AB-AB, ABC-ABC, ABCD-ABCD, etc.
+- Configurable pattern length (2-6 tools) and minimum repetitions (default: 2)
+- Efficient pattern matching using sliding window approach
+- Proper serialization ensures tools with different parameters are treated as distinct
+- State reset after detection to allow recovery
+
+### Algorithm:
+
+1. Maintains history of serialized tool calls
+2. For each new tool call, checks for repeating patterns of various lengths
+3. Uses backward pattern matching from the end of history
+4. Triggers when minimum repetitions threshold is reached
+
+## Testing
+
+- **All existing tests pass**: Ensures backward compatibility
+- **New pattern detection tests**: Cover ABAB, ABCABC, and complex patterns
+- **Edge cases**: Different parameters, insufficient repetitions, mixed patterns
+- **Integration tests**: Verify both consecutive and pattern detection work together
+
+## Verification of Acceptance Criteria
+
+- [x] **Pattern Detection**: Successfully detects non-continuous repetitions like ABABAB
+- [x] **Configurable**: Pattern length and repetition thresholds are configurable
+- [x] **Performance**: Efficient algorithm with bounded history (20 calls max)
+- [x] **No False Positives**: Different tools/parameters don't trigger false detections
+- [x] **Recovery**: State resets after detection to allow user guidance
+
+## Example Scenarios Detected
+
+```typescript
+// These patterns will now be detected:
+toolA -> toolB -> toolA -> toolB  // ABAB pattern
+read_file(file1) -> write_file(file2) -> read_file(file1) -> write_file(file2)  // Real-world example
+toolA -> toolB -> toolC -> toolA -> toolB -> toolC  // ABCABC pattern
+```
+
+## Files Changed
+
+- `src/core/tools/ToolRepetitionDetector.ts` - Enhanced with pattern detection
+- `src/core/tools/__tests__/ToolRepetitionDetector.spec.ts` - Added comprehensive tests
+
+## Checklist
+
+- [x] Code follows project style guidelines
+- [x] Self-review completed
+- [x] Comments added for complex logic
+- [x] All existing tests pass
+- [x] New tests added for pattern detection
+- [x] No breaking changes
+- [x] Performance considerations addressed
+- [x] Backward compatibility maintained