A common sign is a clean looking dashboard that still misses intent drift, unauthorized tool use, or harmful actions hidden inside successful requests. If your traces lack session threading, full arguments, and the authorization reason for each call, you may see activity volume without understanding whether the agent stayed within its mandate or crossed a boundary.
When MCP observability looks healthy but the workflow is still unsafe
The problem is not usually missing telemetry volume, it is missing meaning. In agentic workflows, a request can succeed while the agent has drifted from user intent, overreached its mandate, or taken a harmful path that still looks normal in a trace. If the observability layer does not preserve session context, full tool arguments, and the authorization rationale for each call, it cannot tell safe execution from dangerous execution.
That gap matters because MCP is not just a transport detail, it is part of the control plane that connects an agent to tools and data. A dashboard can show a clean sequence of calls while hiding whether the agent was allowed to do that work, whether the request was scoped correctly, or whether the tool output created an unsafe next step. Useful observability has to reconstruct decision flow, not just record activity counts.
The clearest warning sign is when investigators can explain what happened line by line, but still cannot answer why the agent was permitted to do it or whether the action matched the original task. A second warning sign is when every call looks successful, yet the business outcome is wrong, because the agent followed a plausible but unintended path. That is a control problem, not a logging problem.
What observability must preserve to expose real agent risk
To capture real risk, the trace has to keep the causal chain intact. Session threading links one tool use to the next, so you can see whether the agent stayed in one task or wandered across contexts. Full arguments matter because an API name alone does not reveal the object, scope, or side effect. Authorization reason matters because “allowed” is not the same as “appropriate for this step.”
When those elements are missing, teams end up measuring surface activity instead of security posture. They can count tool invocations, latency, and success rates, but they cannot see intent drift, delegated authority abuse, or boundary crossing. In practice, that means the observability stack may be good enough for performance troubleshooting while still being too weak for security review.
MCP observability should therefore be treated as evidence of control quality, not a reporting feature. A good trace should let a reviewer answer three questions: what the agent tried to do, why the platform allowed it, and whether the call belonged to the current session and objective. If any one of those is absent, the workflow can look compliant while still being exposed.
When hidden risk is more important than visible activity
Signs of weak risk capture usually show up at the edges of the workflow. The agent begins using more tools than the task should require, repeats calls with slightly different parameters, or produces output that seems operationally successful but semantically wrong. Those patterns often indicate overly broad tool access, poor task scoping, or an authorization model that is not enforcing least privilege at the action level.
Another signal is that reviewers can only validate the trace by re-running the workflow themselves. If human understanding depends on replay rather than on recorded evidence, the observability layer is not preserving the most important security facts. In agentic systems, that is especially risky because a single hidden tool call can trigger downstream actions that are hard to unwind.
Security teams should also watch for mismatches between approval and execution. If a user approved a narrow task but the trace shows broader tool use, or if the agent appears to have inherited trust from an earlier step, the system is exposing a delegation gap. That is exactly where harmful actions can hide inside otherwise successful requests.
Risk and Threat Considerations
Weak observability creates a false sense of safety, because the system can look stable while the agent quietly crosses authorization boundaries. In agentic workflows, that makes it harder to detect prompt-driven tool abuse, unintended data access, or actions that are operationally successful but outside the intended mission.
Failure mechanism: The trace records execution events but not enough context to reconstruct intent, scope, and authorization, so reviewers cannot distinguish approved action from unsafe delegation or hidden drift.
Impact: Teams may miss privilege misuse, harmful side effects, or repeated boundary crossings until the workflow has already produced business or security damage.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP Agentic AI Top 10, OWASP Non-Human Identity Top 10, OWASP API Security Top 10 and MITRE ATT&CK address the attack and risk surface, while NIST Zero Trust (SP 800-207) sets the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Agentic AI Top 10 | ASI03 — Identity & Privilege Abuse | Agent tool use can hide privilege abuse and scope creep in traces. |
| ASI02 — Tool Misuse | Missing session context and arguments make tool misuse hard to detect. | |
| ASI08 — Cascading Failures | A hidden bad step can propagate across later agent actions and appear benign. | |
| Recommendation — Enforce per-action authorization and log the approval reason for each agent tool call. Capture full tool inputs and outputs so abnormal or unsafe tool use is reviewable. Trace dependent actions end to end so one unsafe call cannot be mistaken for isolated success. | ||
| OWASP Non-Human Identity Top 10 | NHI-05 — Overprivileged NHI | Agent workflows can appear healthy while using more privilege than the task needs. |
| NHI-02 — Secret Leakage | Full arguments and traces may expose secrets or tokens during agent execution. | |
| NHI-10 — Human Use of NHI | Observability must show when human intent and machine action diverge in shared workflows. | |
| Recommendation — Remove standing excess privilege and review tool access against the minimum task scope. Redact sensitive material while preserving enough context to reconstruct the action chain. Separate human approvals from agent actions so delegated use is visible in audit logs. | ||
| NIST Zero Trust (SP 800-207) | SA — ZTA General Principles | Continuous verification and per-request trust decisions align with agentic workflow observability. |
| PE — Policy Engine and Policy Enforcement Point | Authorization reason and per-action enforcement are central to knowing why a call was allowed. | |
| Recommendation — Verify each agent action continuously instead of trusting prior approval to remain valid. Separate policy decision from execution and log both decisions for every agent action. | ||
| OWASP API Security Top 10 | API5 — Broken Function Level Authorization | Agent tool calls can resemble API function abuse when authorization context is missing. |
| Recommendation — Authorize each function or tool call explicitly and log the decision that allowed it. | ||
| MITRE ATT&CK | T1078 — Valid Accounts | Agent traces can obscure abuse of legitimate access that still looks like normal use. |
| Recommendation — Hunt for legitimate access that is used outside the expected task or session context. | ||
Practitioner Guidance
What to verify: Treat a trace as insufficient unless it can answer session, object, and authorization questions for each tool call. If you cannot reconstruct the user goal, the agent’s current session, and the reason the call was permitted, the control is not giving you a trustworthy risk view.
Common mistake: Do not confuse “successful request” with “safe request.” A workflow can complete normally and still be risky if the agent used the wrong tool, touched the wrong object, or kept operating after the original intent had changed.
What good looks like: The observability record should let a reviewer follow one decision chain from intent to tool use to outcome, with enough detail to justify why each step remained in scope.
Practitioner takeaway: If observability cannot explain why an agent was allowed to act, it is only measuring throughput, not risk.
Related resources from NHI Mgmt Group
- When does just-in-time access reduce risk for agentic AI, and when does it fall short?
- Why do agentic workflows and MCP-based tool use change enterprise risk decisions?
- Why do unmanaged MCP servers create security risk in Claude Code and similar agentic workflows?
- What are the warning signs that an LLM observability programme is missing the real risk?