rucio_deny_rule · Rucio MCP: Risk & Policy

WHAT IT DOES

What rucio_deny_rule does on Rucio

AI agents use rucio_deny_rule to create or update resources in Rucio — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Rucio environment.

WHY IT NEEDS A POLICY

Why rucio_deny_rule needs a policy

Denying a replication rule changes its state in the Rucio system, preventing data replication from proceeding. This is a Write operation (modifying the state of a pending rule) rather than Destructive, as the rule itself likely still exists in a denied state rather than being deleted.

From the tool's definition Deny a replication rule that is waiting for approval

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

rucio_deny_rule Rate-limited

rucio_deny_rule stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "rucio_deny_rule": {
      "limits": [
        {
          "counter": "rucio_deny_rule_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Rucio, so you can run agents against it safely.

FAQ

Questions about rucio_deny_rule

What does the rucio_deny_rule tool do? +

Deny a replication rule that is waiting for approval. It is categorised as a Write tool in the Rucio MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on rucio_deny_rule? +

Register the Rucio MCP server in PolicyLayer and add a rule for rucio_deny_rule: 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 Rucio. Nothing to install.

What risk level is rucio_deny_rule? +

rucio_deny_rule is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit rucio_deny_rule? +

Yes. Add a rate_limit block to the rucio_deny_rule 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.

How do I block rucio_deny_rule completely? +

Set action: deny in the PolicyLayer policy for rucio_deny_rule. 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.

What MCP server provides rucio_deny_rule? +

rucio_deny_rule is provided by the Rucio MCP server (kratsg/rucio-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.