AI agents call unblock_domain to permanently remove resources in OPNSense MCP Server — typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
Removing a domain from a DNS blocklist is an irreversible security action that lifts a previously enforced block. This cannot be automatically undone and directly weakens the firewall's security posture by allowing previously blocked traffic. The action is destructive in the sense that it removes a security control, and the blast radius is high since misuse could expose the network to malicious domains.
From the tool's definition "Remove a domain from the DNS blocklist"
Documented attack patterns abuse exactly the kind of access unblock_domain gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and OPNSense MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for unblock_domain:
{
"version": "1",
"default": "deny",
"hide": [
"unblock_domain"
]
}unblock_domain disappears from the agent's tool list entirely, and any attempt to call it is denied. The rest of the server keeps working.
Free to start. No card required.
Remove a domain from the DNS blocklist. It is categorised as a Destructive tool in the OPNSense MCP Server MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the OPNSense MCP Server MCP server in PolicyLayer and add a rule for unblock_domain: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches OPNSense MCP Server. Nothing to install.
unblock_domain is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the unblock_domain rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for unblock_domain. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
unblock_domain is provided by the OPNSense MCP Server MCP server (vespo92/opnsensemcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 196 OPNSense MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
196 OPNSense MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.