cortex_set_role · Cortex MCP: Risk & Policy

WHAT IT DOES

What cortex_set_role does on Cortex MCP

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

WHY IT NEEDS A POLICY

Why cortex_set_role needs a policy

This tool modifies agent configuration by assigning a role, which in turn governs access to other tools. While it is a write/update operation (reversible in principle), the blast radius is high because misconfiguring or escalating an agent's role could grant it access to destructive or financial tools it otherwise wouldn't have, effectively enabling privilege escalation.

From the tool's definition Set the role for an agent. Roles control which tools the agent can call.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

cortex_set_role Rate-limited

cortex_set_role 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": {
    "cortex_set_role": {
      "limits": [
        {
          "counter": "cortex_set_role_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 Cortex MCP, so you can run agents against it safely.

FAQ

Questions about cortex_set_role

What does the cortex_set_role tool do? +

Set the role for an agent. Roles control which tools the agent can call. It is categorised as a Write tool in the Cortex MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on cortex_set_role? +

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

What risk level is cortex_set_role? +

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

Can I rate-limit cortex_set_role? +

Yes. Add a rate_limit block to the cortex_set_role 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 cortex_set_role completely? +

Set action: deny in the PolicyLayer policy for cortex_set_role. 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 cortex_set_role? +

cortex_set_role is provided by the Cortex MCP server (neuralnexustech/cortex-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.