task_cancel

SERVERClaude Flow SOURCEclaude-flow

Critical RISK CLASS

Category Destructive

Parameters 00 required

Recommended Hiddensee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-github-ruvnet-claude-flow/task-cancel.md

WHAT IT DOES

What task_cancel does on Claude Flow

AI agents call task_cancel to permanently remove resources in Claude Flow, typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.

RISK

Why task_cancel is rated Critical

Cancelling a task with cross-session persistence and dependency tracking is effectively an irreversible operation: once cancelled, dependent tasks and agent assignments may be disrupted. Unlike a soft 'pause', cancellation terminates the task's lifecycle in the persistent store.

From the tool's definition Cancel a task — cancellation of a task is typically irreversible; combined with 'cross-session task persistence' and storage in '.swarm/memory.db', the cancellation persists across sessions and cannot be trivially undone.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs task_cancel safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Claude Flow, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For task_cancel, this is the rule to start with:

task_cancel Hidden

task_cancel is removed from the agent's tool list entirely, so the agent never calls it. The rest of the server keeps working.

View as policy code

policy.json

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

RESTRICT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Claude Flow, apply this rule, and every task_cancel call is checked against it from then on.

FAQ

Questions about task_cancel

What does the task_cancel tool do? +

Cancel a task Use when native TodoWrite is wrong because you need cross-session task persistence, agent assignment, dependency tracking, or completion analytics in the .swarm/memory.db. For in-session checklists native TodoWrite is simpler and faster. It is categorised as a Destructive tool in the Claude Flow 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 task_cancel? +

Register the Claude Flow MCP server in PolicyLayer and add a rule for task_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 Claude Flow. Nothing to install.

What risk level is task_cancel? +

task_cancel 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 task_cancel? +

Yes. Add a rate_limit block to the task_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 task_cancel completely? +

Set action: deny in the PolicyLayer policy for task_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 task_cancel? +

task_cancel is provided by the Claude Flow MCP server (claude-flow). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

More on Claude Flow, and thousands of servers like it.

This server

All 496 Claude Flow tools → Critical-risk tools on this server →

Across the catalogue

sms_cancel_scheduled on Twilio SMS MCP Server →cancel_all_orders on Lighter MCP →task_assignees_remove on Vikunja → All critical-risk MCP tools → The MCP Attack Database →

Guides

Govern code and CI agents →Blast radius →Tool call approval →