heim_update · Heim MCP: Risk & Policy

WHAT IT DOES

What heim_update does on Heim MCP

AI agents invoke heim_update to trigger actions in Heim MCP. 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 heim_update needs a policy

Updating software to the latest version triggers an external operation (downloading and installing a new version of the Heim tool). This is not a simple read or write of user data, but an execution of an install/upgrade process that modifies the system state. While it can be somewhat reversed by downgrading, it does trigger external operations with side effects, placing it in Execute.

From the tool's definition Updates Heim to the latest version

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

heim_update Rate-limited

heim_update 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": {
    "heim_update": {
      "limits": [
        {
          "counter": "heim_update_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 Heim MCP, so you can run agents against it safely.

FAQ

Questions about heim_update

What does the heim_update tool do? +

Updates Heim to the latest version. It is categorised as a Execute tool in the Heim MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on heim_update? +

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

What risk level is heim_update? +

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

Can I rate-limit heim_update? +

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

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

heim_update is provided by the Heim MCP server (nor2-io/heim-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.