now · Agent Bus MCP: Risk & Policy

WHAT IT DOES

What now does on Agent Bus

AI agents use now 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 now needs a policy

This tool modifies agent state or configuration on the shared message bus, making it a Write operation. Severity is medium because unauthorized agent updates could disrupt collaboration workflows or inject malicious behavior into delegated tasks, but the blast radius is limited to the local machine and connected agents.

From the tool's definition Tool name 'now' with description 'Update an agent' indicates modification of agent state or configuration. The verb 'Update' explicitly signals a write operation that modifies data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

now Rate-limited

now 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": {
    "now": {
      "limits": [
        {
          "counter": "now_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 now

What does the now tool do? +

Update an agent. 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 now? +

Register the Agent Bus MCP server in PolicyLayer and add a rule for now: 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 now? +

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

Can I rate-limit now? +

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

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

now 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.