cancellable-wait

Sleeps up to maxMs unless the task runner aborts us.

SERVERFrontmcp SOURCEagentfront/frontmcp

High RISK CLASS

Category Execute

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/frontmcp/cancellable-wait.md

WHAT IT DOES

What cancellable-wait does on Frontmcp

AI agents invoke cancellable-wait to trigger actions in Frontmcp. 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.

RISK

Why cancellable-wait is rated High

This tool executes a sleep/wait operation that can be interrupted by task runner abortion. While not destructive or harmful by itself, it triggers external operations (sleep, cancellation handling) whose effects depend on the maxMs argument and cancellation state.

From the tool's definition Tool performs active execution: "Sleeps up to maxMs unless the task runner aborts us" indicates runtime control flow manipulation and task lifecycle management.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs cancellable-wait safely

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

cancellable-wait Rate-limited

cancellable-wait 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": {
    "cancellable-wait": {
      "limits": [
        {
          "counter": "cancellable-wait_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Frontmcp, apply this rule, and every cancellable-wait call is checked against it from then on.

FAQ

Questions about cancellable-wait

What does the cancellable-wait tool do? +

Sleeps up to maxMs unless the task runner aborts us. It is categorised as a Execute tool in the Frontmcp MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on cancellable-wait? +

Register the Front MCP server in PolicyLayer and add a rule for cancellable-wait: 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 Frontmcp. Nothing to install.

What risk level is cancellable-wait? +

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

Can I rate-limit cancellable-wait? +

Yes. Add a rate_limit block to the cancellable-wait 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 cancellable-wait completely? +

Set action: deny in the PolicyLayer policy for cancellable-wait. 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 cancellable-wait? +

cancellable-wait is provided by the Front MCP server (agentfront/frontmcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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