assign_task · Agent Bus MCP: Risk & Policy

WHAT IT DOES

What assign_task does on Agent Bus

AI agents use assign_task to create or update resources in Agent Bus — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Agent Bus environment.

WHY IT NEEDS A POLICY

Why assign_task needs a policy

This tool modifies the state of a task by transitioning it from 'open' to 'claimed' and assigning it to a specific agent. This is a reversible state change (tasks can be unclaimed/reassigned), making it a Write operation. Misuse could disrupt agent workflows by incorrectly assigning tasks, but it doesn't delete data or execute code.

From the tool's definition Assign an open task directly to an agent, moving it to claimed.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

assign_task Rate-limited

assign_task 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": {
    "assign_task": {
      "limits": [
        {
          "counter": "assign_task_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 Agent Bus, so you can run agents against it safely.

FAQ

Questions about assign_task

What does the assign_task tool do? +

Assign an open task directly to an agent, moving it to claimed. It is categorised as a Write tool in the Agent Bus MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on assign_task? +

Register the Agent Bus MCP server in PolicyLayer and add a rule for assign_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 Agent Bus. Nothing to install.

What risk level is assign_task? +

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

Can I rate-limit assign_task? +

Yes. Add a rate_limit block to the assign_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 assign_task completely? +

Set action: deny in the PolicyLayer policy for assign_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 assign_task? +

assign_task is provided by the Agent Bus MCP server (mustaphasteph/agent-bus). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.