Agent Decision Tracing

The Problem

Cannot trace agent decision-making process (strategy selection, tool use, reasoning steps), making it impossible to debug unexpected agent behavior.

Symptoms

• ❌ Agent chose wrong RAG strategy (Redwood vs Cedar)

• ❌ Cannot see reasoning process

• ❌ Tool selection unexplained

• ❌ Strategy switch mid-conversation mysterious

• ❌ No audit trail of agent decisions

Real-World Example

User: "How do I configure authentication?"

Agent behavior:
→ Uses Cedar strategy (context-aware)
→ Calls tool: get_user_context()
→ Retrieves 15 chunks
→ Switches to Redwood mid-response

Question: Why switch strategies?
→ No logging of decision process
→ Cannot debug
→ Cannot reproduce

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Deep Technical Analysis

Agent Decision Points

Strategy Selection:

Agent must decide:
→ Redwood (standard RAG)
→ Cedar (context-aware)
→ Cypress (advanced agentic)

Decision factors:
→ Query complexity
→ Conversation history
→ User role/permissions
→ Available context

Log decision:
{
  "query": "...",
  "strategy_selected": "Cedar",
  "reasoning": "Complex query requiring user context",
  "confidence": 0.85
}

Tool Selection:

Agent has tools:
→ search_knowledge_base()
→ get_user_permissions()
→ query_database()
→ call_external_api()

Agent decides: Use search_knowledge_base() + get_user_permissions()

Log:
{
  "tools_available": [...],
  "tools_selected": ["search_knowledge_base", "get_user_permissions"],
  "reasoning": "Need both knowledge base and user context"
}

Reasoning Chain Logging

Step-by-Step Trace:

{
  "query": "Can Alice access Production DB?",
  "reasoning_chain": [
    {
      "step": 1,
      "thought": "Need to find Alice's team",
      "action": "search_knowledge_base('Alice team')",
      "result": "Alice is in Engineering team"
    },
    {
      "step": 2,
      "thought": "Need team's database access",
      "action": "search_knowledge_base('Engineering database access')",
      "result": "Engineering has access to Prod-DB"
    },
    {
      "step": 3,
      "thought": "Combine findings",
      "conclusion": "Yes, Alice can access Prod-DB (via Engineering team)"
    }
  ]
}

Chain-of-Thought Visibility:

Agent uses chain-of-thought prompting:
→ LLM outputs thinking process
→ Capture and log this

Example output:
"Let me think step-by-step:
1. Alice is in Engineering team (from doc_123)
2. Engineering team has Prod-DB access (from doc_456)
3. Therefore, Alice has access"

Log this intermediate reasoning

Strategy Switch Detection

Mid-Conversation Changes:

Turn 1: Strategy = Redwood
Turn 2: Strategy = Cedar

Why switch?
→ Log trigger:
{
  "previous_strategy": "Redwood",
  "new_strategy": "Cedar",
  "trigger": "User asked follow-up requiring context",
  "timestamp": "..."
}

Enables debugging strategy oscillation

Fallback Triggers:

Agent tries Cedar:
→ Fails to find context
→ Falls back to Redwood

Log fallback:
{
  "attempted_strategy": "Cedar",
  "fallback_strategy": "Redwood",
  "reason": "User context unavailable",
  "attempt_duration_ms": 1500
}

Decision Confidence Tracking

Confidence Scores:

Agent decisions have uncertainty:
{
  "strategy": "Cedar",
  "confidence": 0.75,
  "alternatives": [
    {"strategy": "Redwood", "score": 0.60},
    {"strategy": "Cypress", "score": 0.45}
  ]
}

Low confidence (< 0.70):
→ Flag for review
→ May indicate ambiguous query
→ Consider asking user for clarification

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How to Solve

Log agent strategy selection with reasoning + trace tool calls (which tools, why, results) + capture chain-of-thought reasoning steps + monitor strategy switches and log triggers + track decision confidence scores + implement replay capability for agent decisions + alert on low-confidence decisions (< 0.70) + build agent decision timeline visualization + test decision quality with eval set. See Agent Tracing.