claim_next_task · AT MCP: Risk & Policy

WHAT IT DOES

What claim_next_task does on ATMcp

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

WHY IT NEEDS A POLICY

Why claim_next_task needs a policy

This tool modifies task state in a distributed system, which is a reversible write operation (tasks can be unclaimed or reassigned). It does not execute arbitrary code, delete data, or move money. The 'medium' severity reflects that in a multi-agent team system, incorrect task claiming could disrupt workflow orchestration and task assignments, but the operation is reversible (via cancel_directive or reassignment).

From the tool's definition Tool claims (reserves) an open task by marking it as claimed, modifying shared task state. The description indicates state mutation: 'Claim the highest-priority eligible...open task' implies transitioning task from unclaimed to claimed status.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

claim_next_task Rate-limited

claim_next_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": {
    "claim_next_task": {
      "limits": [
        {
          "counter": "claim_next_task_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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

FAQ

Questions about claim_next_task

What does the claim_next_task tool do? +

Claim the highest-priority eligible (deps satisfied) open task in one round-trip. It is categorised as a Write tool in the ATMcp MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on claim_next_task? +

Register the AT MCP server in PolicyLayer and add a rule for claim_next_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 ATMcp. Nothing to install.

What risk level is claim_next_task? +

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

Can I rate-limit claim_next_task? +

Yes. Add a rate_limit block to the claim_next_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 claim_next_task completely? +

Set action: deny in the PolicyLayer policy for claim_next_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 claim_next_task? +

claim_next_task is provided by the AT MCP server (midcheck/atmcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.