vm_prometheus_write

THE RISK

Medium Risk

Why vm_prometheus_write needs a policy

This tool writes/imports time-series data into VictoriaMetrics. While the data addition is reversible in principle (via deletion), importing untrusted or malicious metric data could poison the metrics database, affect monitoring/alerting systems, or consume storage resources. The severity is medium rather than high because the impact is localized to metric data integrity rather than causing direct external harm.

From the tool's definition Tool name is 'vm_prometheus_write' and description states it will 'mport Prometheus exposition format data into VictoriaMetrics' (import, with apparent typo). The 'write' verb and 'import' action indicate data is being created/added to the system.

Documented attack patterns abuse exactly the kind of access vm_prometheus_write gives an agent:

POLICY

How to control vm_prometheus_write

PolicyLayer is an MCP gateway — it sits between your AI agents and VictoriaMetrics-mcp-server, and nothing reaches the server without passing your rules. This is the rule we recommend for vm_prometheus_write:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "vm_prometheus_write": {
      "limits": [
        {
          "counter": "vm_prometheus_write_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

vm_prometheus_write 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.

Create a free account and register VictoriaMetrics-mcp-server — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

LIMIT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More VictoriaMetrics-mcp-server tools

Write vm_data_write Write data to the VM database Read vm_label_values Get all unique values for a specific label Read vm_labels Get all unique label names Read vm_query Query current value of a time series Read vm_query_range Query time series over a time range

All 6 VictoriaMetrics-mcp-server tools →

Write tools on other servers

M-Team MCP Server download_torrent YouTube MCP Server generate_video_title Android Forensics ADB MCP Server combine_reports 0xarchive web3_signup

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Argument validation → Checking tool call arguments against schema and policy before they run.
Scoped token → Per-person credentials that grant a defined subset of servers and tools.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about vm_prometheus_write

What does the vm_prometheus_write tool do? +

mport Prometheus exposition format data into VictoriaMetrics. It is categorised as a Write tool in the VictoriaMetrics-mcp-server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on vm_prometheus_write? +

Register the VictoriaMetrics-mcp-server MCP server in PolicyLayer and add a rule for vm_prometheus_write: 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 VictoriaMetrics-mcp-server. Nothing to install.

What risk level is vm_prometheus_write? +

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

Can I rate-limit vm_prometheus_write? +

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

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

vm_prometheus_write is provided by the VictoriaMetrics-mcp-server MCP server (yincongcyincong/victoriametrics-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every VictoriaMetrics-mcp-server tool call.

Start from VictoriaMetrics-mcp-server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →