session_cancel · Iris MCP: Risk & Policy

WHAT IT DOES

What session_cancel does on Iris MCP

AI agents invoke session_cancel to trigger actions in Iris MCP. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why session_cancel needs a policy

Cancelling a running operation is an active intervention that terminates an in-progress process. This is an Execute-category action because it triggers an external operation (stopping a session), and its effects depend on what session is targeted. It is not purely destructive (it doesn't delete data irreversibly) but it does affect the runtime state of a session, making Execute the most appropriate category.

From the tool's definition Cancel a running session operation

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

session_cancel Rate-limited

session_cancel stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "session_cancel": {
      "limits": [
        {
          "counter": "session_cancel_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about session_cancel

What does the session_cancel tool do? +

Cancel a running session operation. It is categorised as a Execute tool in the Iris MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on session_cancel? +

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

What risk level is session_cancel? +

session_cancel is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit session_cancel? +

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

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

session_cancel is provided by the Iris MCP server (jenova-marie/iris-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.