register_agent · Agent-Comm-Hub MCP: Risk & Policy

WHAT IT DOES

What register_agent does on Agent-Comm-Hub

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

WHY IT NEEDS A POLICY

Why register_agent needs a policy

The tool creates a new agent registration and generates security credentials (api_token shown only once). This is a Write operation because it adds and modifies system state (new agent in the registry, new credentials issued). Severity is high because a compromised token grants API access to the Hub, and an attacker could register unauthorized agents.

From the tool's definition Tool description states 'register new Agent to Hub' and 'returns agent_id and api_token'. This creates new credentials and registers an entity in the system, modifying the agent registry irreversibly from the Hub's perspective.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

register_agent Rate-limited

register_agent 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": {
    "register_agent": {
      "limits": [
        {
          "counter": "register_agent_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-Comm-Hub, so you can run agents against it safely.

FAQ

Questions about register_agent

What does the register_agent tool do? +

注册新 Agent 到 Hub。需要有效的邀请码。注册成功返回 agent_id 和 api_token（仅显示一次）。. It is categorised as a Write tool in the Agent-Comm-Hub MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on register_agent? +

Register the Agent-Comm-Hub MCP server in PolicyLayer and add a rule for register_agent: 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-Comm-Hub. Nothing to install.

What risk level is register_agent? +

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

Can I rate-limit register_agent? +

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

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

register_agent is provided by the Agent-Comm-Hub MCP server (liuboacean/agent-comm-hub). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.