Summary

This PR fixes the flaky test_agent_with_tool_steering_e2e integration test in tests_integ/steering/test_tool_steering.py.

Problem

The test was failing intermittently because:

1. Bug in LLMSteeringHandler initialization: The context_providers or [LedgerProvider()] pattern treated an empty list as falsy, defaulting to [LedgerProvider()] even when explicitly passed an empty list
2. Soft guidance message: The steering handler's error message ("Consider this approach and continue") was too soft, causing the main agent to ask clarifying questions instead of following the guidance
3. Ambiguous test system prompt: The steering LLM analyzed ledger context data showing "pending" operations, which confused the main agent into thinking there was a duplicate request

Root Cause Analysis

When the test ran:

1. Agent tried to call send_email
2. LedgerProvider added the tool call to the ledger with "pending" status
3. Steering LLM saw this context and returned guidance like "Context data shows a duplicate send_email call..."
4. Main agent interpreted the "pending" information as uncertainty and asked the user instead of switching to send_notification

Solution

1. Fix LLMSteeringHandler context_providers handling

# Before (buggy)
providers = context_providers or [LedgerProvider()]

# After (correct)
providers = [LedgerProvider()] if context_providers is None else context_providers

2. Make guidance message more directive

# Before
f"Tool call cancelled given new guidance. {action.reason}. Consider this approach and continue"

# After
f"Tool call cancelled. {action.reason} You MUST follow this guidance immediately."

3. Improve test system prompt

Made the system prompt explicit, rule-based, and disabled context providers to prevent ledger data from influencing the steering decision.

Testing

• Ran the test 10+ times in succession with 100% pass rate
• All unit tests pass
• All other integration tests in the steering module pass

Files Changed

• src/strands/experimental/steering/core/handler.py - More directive guidance message
• src/strands/experimental/steering/handlers/llm/llm_handler.py - Fix context_providers handling
• tests/strands/experimental/steering/core/test_handler.py - Update unit test expectation
• tests_integ/steering/test_tool_steering.py - Improved test configuration