Because they centralize the discovery of machine-consumable tools, they also centralize the point where policy can fail. If the registry exposes stale, excessive, or unowned tool entries, agents can reach services that were never meant to be broadly discoverable. That makes registry governance part of NHI lifecycle control.
Why This Matters for Security Teams
MCP registries change the control plane for discovery. Instead of each agent, service, or integration knowing a narrow tool set, the registry becomes the place where tools are published, discovered, and trusted. That creates a new governance problem: if the registry contains stale, excessive, or unowned entries, the attack surface expands even when the underlying service has not changed.
This is why registry governance is not just catalog hygiene. It affects entitlement review, ownership, lifecycle state, and the ability to prove that a tool should still be reachable by an agent. The issue is especially sharp for autonomous systems, where tool use can be chained quickly and at machine speed. NHI programmes already struggle with visibility gaps; NHIMG research shows only 1.5 out of 10 organisations are highly confident in securing NHIs, and 85% lack full visibility into third-party OAuth-connected services in The State of Non-Human Identity Security.
In practice, many security teams discover registry overexposure only after an agent has already found and used a tool that was never meant to be broadly discoverable.
How It Works in Practice
An MCP registry should be treated like a governed trust source, not a convenience layer. At minimum, each tool entry needs a named owner, a business purpose, a lifecycle state, a policy classification, and a review timestamp. If the registry is allowed to expose tools without those attributes, security teams lose the ability to distinguish approved automation from orphaned capability.
Current guidance suggests combining identity controls with policy enforcement at discovery and invocation time. That means the registry should not only list tools, but also enforce who or what can see them, under which conditions, and for how long. For autonomous workloads, the better pattern is workload identity plus runtime policy evaluation, not static allowlists alone. Standards work around agentic systems is still emerging, but the direction is clear in OWASP Agentic AI Top 10 and NIST Cybersecurity Framework 2.0.
- Use workload identity to prove the calling agent or service is authentic before registry access is granted.
- Issue just-in-time, short-lived credentials for tool registration and tool invocation.
- Bind tool visibility to policy, not to broad team membership or inherited network reachability.
- Revoke or retire entries when ownership, scope, or dependency state changes.
The operational model aligns with the lifecycle view in Ultimate Guide to NHIs — Lifecycle Processes for Managing NHIs, where discovery, ownership, rotation, and retirement are treated as control points rather than administrative tasks. These controls tend to break down when multiple teams can publish into the same registry without a single authoritative ownership workflow, because stale entries survive long after the original automation has changed.
Common Variations and Edge Cases
Tighter registry control often increases friction for developers and platform teams, requiring organisations to balance fast tool onboarding against stronger governance. That tradeoff becomes visible in hybrid environments, where multiple registries, tenants, or clusters expose overlapping tools and no single source of truth exists.
There is no universal standard for MCP registry governance yet, so current best practice is evolving. Some organisations will enforce approval before publication, while others will allow self-service registration with automated policy checks and periodic recertification. The right choice depends on how much tool risk is introduced by the registry itself versus the services behind it. For high-impact environments, security teams should assume that registry misuse can become an identity problem, not just an inventory problem.
That is why registry controls should be reviewed alongside broader NHI practices documented in Top 10 NHI Issues and the implementation patterns discussed in the Ultimate Guide to NHIs. In shared platforms, the hardest edge case is usually not malicious publication but abandoned entries that remain technically valid after the owning team has moved on.
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 and CSA MAESTRO address the attack and risk surface, while NIST AI RMF set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Agentic AI Top 10 | A3 | Covers tool abuse and unsafe agent interactions through discovery layers. |
| CSA MAESTRO | GOVERN | Registry ownership and lifecycle are governance concerns for agentic systems. |
| NIST AI RMF | GOVERN | Registry trust decisions need documented accountability and risk oversight. |
Treat MCP registry access as a gated agent capability and enforce policy before tool use.
