Agent Tool Invocation Logging
Description
Every LLM agent tool invocation logged with input, output, authorisation context, and timing. Forensic trail for agent behaviour.
⚠️ Risk Impact
Without invocation logging, agentic LLM behaviour is opaque. Post-incident reconstruction is impossible; root-cause analysis stalls; recurrence is inevitable.
🔍 How EchelonGraph Detects This
EchelonGraph's Tier 1 Cloud Scanner automatically checks for this condition across all connected cloud accounts. Violations are flagged as high-severity findings with remediation guidance.
🔧 Remediation
Log every agent tool call (read + write) with structured fields: tool name, input args, output, principal, timestamp, decision rationale. Centralise to SIEM; retain 90+ days; cryptographically tamper-evident where possible.
💀 Real-World Attack Scenario
An LLM-based customer-support agent made an unauthorised refund. Investigation could not reconstruct the decision because tool-invocation logs covered API calls but not the agent's reasoning (chain-of-thought) or the input prompt that produced the decision. Resolution: manual customer-by-customer audit of $80K+ in suspect refunds.
💰 Cost of Non-Compliance
Insufficient agent logging: 3.2× longer incident investigation (DORA 2024). Avg per-incident investigation cost without logs: $180K (PwC).
📋 Audit Questions
- 1.Show me the agent tool-invocation log structure.
- 2.Are chain-of-thought / reasoning steps captured?
- 3.Where are logs stored? For how long?
- 4.Are logs cryptographically tamper-evident?
🎯 MITRE ATT&CK Mapping
🏗️ Infrastructure as Code Fix
resource "google_logging_log_sink" "agent_invocations" {
name = "llm-agent-invocations"
destination = "storage.googleapis.com/${google_storage_bucket.agent_logs.name}"
filter = "resource.type=\"k8s_container\" AND jsonPayload.event=\"agent_tool_invocation\""
unique_writer_identity = true
}
resource "google_storage_bucket" "agent_logs" {
name = "llm-agent-logs"
location = "EU"
retention_policy { retention_period = 31536000 } # 1 year
}⚡ Common Pitfalls
- ⛔Logging tool API calls but not the agent's input prompt + reasoning
- ⛔Mutable log storage — can't trust forensics
- ⛔Short retention (<30 days) — incidents surface after the window
📈 Business Value
Agent invocation logs are the foundation of agentic LLM trustworthiness. Material for any agent product handling regulated decisions or financial actions.
⏱️ Effort Estimate
2-3 weeks for structured logging + immutable sink
EchelonGraph auto-instruments LangChain / LlamaIndex / AutoGPT agents with full invocation logging
🔗 Cross-Framework References
Automate OWASP LLM Top 10 LLM-AGENT-AUDIT compliance
EchelonGraph continuously monitors this control across all your cloud accounts.
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