MCP registry-driven tool discovery changes agent governance

At a glance

What this is: Kong is framing dynamic MCP tool discovery as the answer to brittle, hardcoded agent integrations, with runtime registry lookup becoming the new operating model.

Why it matters: This matters because IAM, NHI, and agentic AI programmes now need to govern tool discovery, access boundaries, and execution authority together instead of treating them as separate problems.

👉 Read Kong's analysis of dynamic MCP tool discovery in Konnect

Context

Dynamic tool discovery is the governance problem here, not just an integration convenience. When an AI agent can discover capabilities at runtime, the security question changes from what the agent was allowed to call at build time to what it is permitted to find, select, and execute in the moment.

That shift puts MCP registries squarely into identity and access governance. The registry becomes a control plane for approved capabilities, environment scoping, and access boundaries, which means teams must think about it the same way they think about identity directories, entitlement stores, and privileged execution paths.

The article’s examples are a typical expression of where agentic systems are heading: fewer fixed integrations, more runtime selection, and more dependence on the trustworthiness of the discovery layer.

Key questions

Q: How should security teams govern dynamic tool discovery for AI agents?

A: Security teams should treat tool discovery as a governed entitlement flow, not as a convenience feature. The registry should be segmented by environment and ownership, its metadata should be validated, and agent access should be limited to the minimum set of discoverable capabilities needed for the task. Discovery and execution should remain separate controls.

Q: What breaks when AI agents discover tools at runtime instead of using hardcoded lists?

A: Hardcoded lists assume the tool set is stable enough to be embedded in code. That breaks when services change frequently, environments differ, or new tools appear without redeploying the agent. Runtime discovery shifts the trust boundary to the registry, so misclassified or overexposed tools can be selected immediately.

Q: How do you know if an MCP registry is being governed well?

A: A well-governed registry has clear ownership, environment scoping, and consistent metadata, and it only exposes capabilities that are approved for the agent’s operating context. If agents can discover tools that they should not be able to use, the governance model is too loose.

Q: What is the difference between tool registration and tool execution in agentic systems?

A: Tool registration makes a capability visible in the registry, while tool execution allows an agent to invoke it. Those controls should not be treated as the same thing. A tool can be registered for discoverability without being universally executable, which is essential for least-privilege agent governance.

Technical breakdown

Why hardcoded MCP server lists fail in enterprise agents

Hardcoded tool lists work only when the environment is stable and the agent’s task set is narrow. In practice, enterprise systems change continuously: services appear, versions drift, environments differ, and approved capabilities vary by team or domain. Static configuration forces redeployment every time the tool landscape changes, which couples agent logic to infrastructure volatility. Dynamic discovery decouples those layers by letting the agent query a registry for current options at runtime. That improves scalability, but it also moves the trust boundary to the registry itself and to the metadata that describes each tool.

Practical implication: treat the registry as a governed source of truth, not a convenience layer.

How an MCP registry becomes the control point for agent permissions

An MCP registry is more than a directory. It groups local and remote servers, attaches metadata such as environment, ownership, and access boundaries, and exposes structured lookup for agents and applications. That makes discovery policy-driven instead of embedded in code. The agent does not need to know every tool in advance, but it does need a trustworthy answer to which tools exist, where they live, and whether they are appropriate for the requested task. In identity terms, the registry is where discoverability, approval scope, and execution eligibility converge.

Practical implication: align registry metadata with approval domains, environment boundaries, and ownership records.

Why runtime selection changes the risk profile of agentic execution

Once a tool is discovered dynamically, the execution path is no longer fixed at deployment. The agent can search, select, and invoke a server based on the current request and the registry response. That is valuable for flexibility, but it also means the agent’s effective privilege is shaped at runtime by what the registry exposes. If a capability is mislabelled, overexposed, or registered in the wrong boundary, the agent can act on it immediately. The architectural risk is not just tool sprawl. It is uncontrolled runtime authority.

Practical implication: verify that registry search results map to least-privilege execution, not just to availability.

NHI Mgmt Group analysis

MCP registries are becoming identity control planes for agentic systems. The article shows that capability discovery is no longer a build-time concern. Once agents can query a registry at runtime, the registry becomes the gatekeeper for which tools exist, which environments they belong to, and which executions are legitimate. That is an identity problem as much as an integration problem. Practitioners should treat registry governance as part of agent entitlement management, not as adjacent platform plumbing.

Static tool configuration was designed for fixed execution paths, not runtime discovery. That assumption fails when an agent can search for capabilities after it receives a prompt and then select a tool dynamically. The implication is that governance cannot rely on predeclared integrations alone, because the actual execution path is decided at runtime. This is the point where agentic behaviour starts to outgrow conventional configuration management.

Dynamic capability discovery is the right term for the pattern, but the governance gap is tool provenance. The article’s architecture depends on the registry being the definitive source of truth for available MCP servers. If provenance, environment tagging, and access boundaries are wrong, the agent will faithfully execute the wrong capability with no additional human checkpoint. Practitioners should focus on where tool identity is asserted and how that assertion is controlled.

Agentic systems need discovery governance before they need more tools. The enterprise failure mode is not just that agents lack access. It is that they can access the wrong thing too easily once discovery is made programmable. That puts change control, ownership, and environment separation ahead of tool expansion in the maturity model. Teams should prioritise governance of the registry before scaling the registry itself.

Runtime tool selection widens the attack surface unless the registry is tightly bounded. The article’s model separates search from execution, which is architecturally clean but operationally sensitive. Search results can become an unintended privilege catalog if the registry exposes more than the agent should see. Practitioners need to think in terms of discoverability scopes, not just connection endpoints.

From our research:

• 98% of companies plan to deploy even more AI agents within the next 12 months, despite documented rogue behaviour in 80% of current deployments, according to AI Agents: The New Attack Surface report.
• Only 52% of companies can track and audit the data their AI agents access, leaving 48% with a complete blind spot for compliance and breach investigation.
• Use OWASP Agentic Applications Top 10 to map discovery, tool-use, and access-control risks before agents inherit broader runtime authority.

What this signals

Dynamic discovery will outgrow static approvals unless teams redesign governance around runtime selection. As agents begin to query registries for capabilities instead of relying on fixed integrations, the practical question becomes whether approval records still describe the real execution path. That means registry metadata, ownership, and environment separation need to become first-class programme controls rather than platform details.

The next maturity step is not more tools, but better control over what tools are visible to which agent in which context. Teams that already struggle to track access paths across service accounts and workloads will find runtime discovery even harder to govern unless they anchor it in a lifecycle model and review process.

Agentic programmes should expect the control conversation to shift from provisioning to discoverability. When a registry can add new capabilities without code changes, the operational risk is less about deployment speed and more about whether the discovery layer is exposing authority faster than governance can classify it.

For practitioners

• Define registry-level approval boundaries Separate development, staging, and production MCP registries so agents only discover tools appropriate to the environment they operate in.
• Bind tool metadata to ownership and purpose Require each registered MCP server to carry clear namespace, owner, execution context, and business purpose metadata before it can be exposed to agents.
• Review discovery queries as entitlement surfaces Test what an agent can discover before you test what it can execute, because search results can reveal capabilities that should remain hidden.
• Separate registration from execution permission Do not assume a tool that is registered should also be executable by every agent that can see it. Use distinct access checks for discovery and invocation.

Key takeaways

• MCP registries move the security problem from static integration lists to runtime governance of discoverable capabilities.
• The main risk is not that agents cannot find tools, but that they can find and use the wrong tools too easily.
• Teams should govern registry boundaries, metadata quality, and execution permission as separate controls before scaling agentic deployments.

Key terms

• MCP Registry: A centralized directory for model context protocol servers and their metadata. In practice, it becomes the place where agents discover what tools exist, where they are hosted, and which environments or boundaries they belong to. For governance teams, it is also a control surface for scope and approval.
• Dynamic Tool Discovery: A runtime pattern where an agent asks a registry or directory what tools are available before deciding what to use. This differs from hardcoded integration because the tool list can change without redeploying the agent. The governance challenge is keeping discovery aligned to least privilege.
• Runtime Authority: The effective permission an agent has at the moment it searches, selects, and invokes a tool. It is shaped by what the registry exposes, what metadata says about the tool, and what execution controls are in place. In agentic systems, runtime authority is often broader than teams assume.

Deepen your knowledge

NHI governance, agentic AI identity, and machine identity security are core topics in our NHI Foundation Level course, the industry's only accredited NHI security programme. If you are responsible for identity security strategy or NHI governance in your organisation, it is worth exploring.

This post draws on content published by Kong: Leveraging the MCP Registry in Kong Konnect for Dynamic Tool Discovery. Read the original.