cancel_task

THE RISK

Critical Risk

Why cancel_task needs a policy

Cancelling a task is likely irreversible — a running or pending task that is cancelled cannot simply be 'uncancelled' and its progress is lost. This makes it a destructive action rather than a simple write/update. The blast radius is medium since it affects a single task and its associated work, but does not delete broader project data.

From the tool's definition Cancel pending/running task

Documented attack patterns abuse exactly the kind of access cancel_task gives an agent:

POLICY

How to control cancel_task

PolicyLayer is an MCP gateway — it sits between your AI agents and N2n Nexus, and nothing reaches the server without passing your rules. This is the rule we recommend for cancel_task:

policy.json

{
  "version": "1",
  "default": "deny",
  "hide": [
    "cancel_task"
  ]
}

cancel_task disappears from the agent's tool list entirely, and any attempt to call it is denied. The rest of the server keeps working.

Create a free account and register N2n Nexus — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

RESTRICT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More N2n Nexus tools

Destructive host_delete_project [ASYNC][Host] Delete project. Irreversible. Returns taskId. Destructive host_maintenance [Host] Manage logs: Execute start_meeting Start new meeting session. Returns meeting ID. Write archive_meeting [Host] Archive closed meeting. Read-only after. Write create_task [ASYNC] Create background task. Returns taskId for polling. Write end_meeting [Host] End active meeting. Locks history. Write register_session_context Declare active project. Format: [prefix]_[name] (e.g., Write rename_project [ASYNC] Rename project ID with cascading relation updates. Returns taskId.

All 22 N2n Nexus tools →

Destructive tools on other servers

Android Forensics ADB MCP Server create_full_backup 0xarchive web3_revoke_key Frida Game Hacking MCP clear_scan cPanel MCP Server clear_spam_box

Go deeper

Critical-risk tools in N2n Nexus → Every critical-risk tool this server exposes, in one view.
All critical-risk MCP tools → Every critical-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Blast radius → How much damage one compromised or confused agent can do — and how to bound it.
Tool call approval → Approval gates on individual tool calls: auto-allow, prompt, or deny.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about cancel_task

What does the cancel_task tool do? +

Cancel pending/running task. It is categorised as a Destructive tool in the N2n Nexus MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.

How do I enforce a policy on cancel_task? +

Register the N2n Nexus MCP server in PolicyLayer and add a rule for cancel_task: 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 N2n Nexus. Nothing to install.

What risk level is cancel_task? +

cancel_task is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.

Can I rate-limit cancel_task? +

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

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

cancel_task is provided by the N2n Nexus MCP server (n2ns/n2n-nexus). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every N2n Nexus tool call.

Start from N2n Nexus, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →