halt · Jlink MCP: Risk & Policy

WHAT IT DOES

What halt does on Jlink

AI agents invoke halt to trigger actions in Jlink. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why halt needs a policy

This tool halts/pauses the execution of a microcontroller CPU. It triggers an external operation (stopping a running embedded system) whose effect is immediate and significant — halting a CPU controlling real hardware (motors, sensors, safety systems) could cause physical consequences.

From the tool's definition 暂停目标 CPU 执行 (Halt target CPU execution)

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

halt Rate-limited

halt stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "halt": {
      "limits": [
        {
          "counter": "halt_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about halt

What does the halt tool do? +

暂停目标 CPU 执行。. It is categorised as a Execute tool in the Jlink MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on halt? +

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

What risk level is halt? +

halt is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit halt? +

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

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

halt is provided by the Jlink MCP server (xun123456/jlink-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.