nexus_claim_job · NexusToken MCP: Risk & Policy

WHAT IT DOES

What nexus_claim_job does on NexusToken

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

WHY IT NEEDS A POLICY

Why nexus_claim_job needs a policy

Claiming a job is a state transition (Write) that assigns the job to the provider. It is not destructive or financial, and it does modify persistent state. The blast radius is medium — misclaiming a job could disrupt workflow but is likely recoverable by rejecting or releasing the job.

From the tool's definition 'pick up a QUEUED job on a spec you own. Transitions' — the tool changes the state of a job from QUEUED to a claimed/in-progress state, which is a reversible state modification

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

nexus_claim_job Rate-limited

nexus_claim_job 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": {
    "nexus_claim_job": {
      "limits": [
        {
          "counter": "nexus_claim_job_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 NexusToken, so you can run agents against it safely.

FAQ

Questions about nexus_claim_job

What does the nexus_claim_job tool do? +

Provider tool: pick up a QUEUED job on a spec you own. Transitions. It is categorised as a Write tool in the NexusToken MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on nexus_claim_job? +

Register the NexusToken MCP server in PolicyLayer and add a rule for nexus_claim_job: 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 NexusToken. Nothing to install.

What risk level is nexus_claim_job? +

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

Can I rate-limit nexus_claim_job? +

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

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

nexus_claim_job is provided by the NexusToken MCP server (bobuilds/nexustoken-sdk). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.