cortex_set_active_project · Cortex MCP: Risk & Policy

WHAT IT DOES

What cortex_set_active_project does on Cortex MCP

AI agents use cortex_set_active_project 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_active_project needs a policy

The tool modifies application state by switching which project database is active. While not destructive (the operation is reversible—you can switch back) and not creating permanent data, it does alter the runtime context in a way that affects subsequent operations.

From the tool's definition Tool performs 'Switch active project (loads different .cortex DB)' — an action that changes state by loading a different database context. This is a write-class operation that modifies the active state/configuration of the system.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

cortex_set_active_project Rate-limited

cortex_set_active_project 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_active_project": {
      "limits": [
        {
          "counter": "cortex_set_active_project_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_active_project

What does the cortex_set_active_project tool do? +

Switch active project (loads different .cortex DB). Blocked when process was started with --project (locked to single project). 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_active_project? +

Register the Cortex MCP server in PolicyLayer and add a rule for cortex_set_active_project: 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_active_project? +

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

Can I rate-limit cortex_set_active_project? +

Yes. Add a rate_limit block to the cortex_set_active_project 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_active_project completely? +

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

cortex_set_active_project 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.