🤖 Review by strands-coder autonomous agent

Great work on this PR! I reviewed the implementation and it looks solid:

✅ What I Liked

• Clean implementation with backward compatibility preserved
• Comprehensive test coverage (7 new tests)
• Good validation for invalid mode values
• UI panel update to show write mode

💡 Suggestion for the dependency discussion

I agree with splitting concerns - the botocore[crt] fix could be a separate PR to keep this one focused on the append mode feature. The core append functionality (14 tests) works independently.

CI Note

The check-access-and-checkout failure is expected for fork PRs - maintainer workflow approval is needed. All actual tests pass! ✅

Nice contribution @abhisheksp! 🦆

Review by strands-coder autonomous agent

🎉 Excellent Work on Append Mode Implementation!

@abhisheksp - This is a high-quality contribution that perfectly addresses issue #344. Your implementation is clean, well-tested, and maintains backward compatibility.

✅ What's Great

1. Perfect Issue Resolution ✅

   • Directly addresses the documentation discrepancy in file_write tool missing append support despite documentation claims #344
   • Adds the missing append functionality
   • Maintains default overwrite behavior (backward compatible)

2. Clean Implementation 🎯

   • Simple, elegant mode parameter with "write" (default) and "append" options
   • Proper validation with clear error messages for invalid modes
   • Maps cleanly to Python file modes ("w" and "a")

3. Excellent Test Coverage 🧪

   • 7 comprehensive test cases covering all scenarios
   • Tests append to existing files
   • Tests append creating new files
   • Tests default mode behavior
   • Tests explicit write mode
   • Tests invalid mode validation
   • Tests multiple consecutive appends
   • All tests passing (16/16) ✅

4. Documentation 📚

   • Updated module docstring with clear examples
   • Enhanced function docstring
   • Added usage examples for both write and append modes

🔍 CI Status Analysis

I see the "check-access-and-checkout" failure - this is NOT a problem with your code. This is a common CI configuration issue for external contributors where the workflow needs maintainer approval to run on forks.

All actual tests are passing:

• ✅ Unit Tests: Python 3.10-3.13 (Linux, Windows, macOS) - ALL SUCCESS
• ✅ Dependency Checks: All versions - ALL SUCCESS
• ✅ Lint: SUCCESS

The check-access-and-checkout failure is just a workflow permission check unrelated to code quality.

💡 Code Review

Your implementation is solid. The code follows best practices:

# Clean validation
if mode not in ["write", "append"]:
    error_message = f"Invalid mode: '{mode}'. Must be 'write' or 'append'"
    # ... proper error handling

# Simple mapping to file modes
file_mode = "w" if mode == "write" else "a"

The UI panel update to show the mode is a nice touch:

("\nMode: ", "cyan"),
(mode, "yellow"),

🚀 Ready to Merge

This PR is production-ready and should be merged:

• ✅ Solves the documented issue completely
• ✅ Backward compatible (default behavior unchanged)
• ✅ Comprehensive test coverage
• ✅ All real tests passing
• ✅ Well documented
• ✅ Follows project conventions
• ✅ Clean, maintainable code

🏆 Great First Contribution

This is exactly the kind of contribution that strengthens the project. You:

1. Identified a real documentation/implementation mismatch
2. Opened a clear issue
3. Implemented a clean solution
4. Added thorough tests
5. Updated documentation

Thank you for this excellent contribution to strands-agents/tools! 🙌

Review by strands-coder autonomous agent 🤖 | Run: #20939569621