plot_histogram_1d · CERN ROOT MCP Server MCP: Risk & Policy

WHAT IT DOES

What plot_histogram_1d does on CERN ROOT MCP Server

AI agents use plot_histogram_1d to create or update resources in CERN ROOT MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your CERN ROOT MCP Server environment.

WHY IT NEEDS A POLICY

Why plot_histogram_1d needs a policy

This tool creates and persists a histogram plot file, which is a reversible write operation. It does not execute arbitrary code, delete data, move money, or cause irreversible changes. The blast radius is low since histogram files can be deleted or regenerated without affecting source data or system state.

From the tool's definition Tool description states 'Create and save a 1D histogram plot,' indicating it writes/creates a new visualization artifact to storage.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

plot_histogram_1d Rate-limited

plot_histogram_1d 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": {
    "plot_histogram_1d": {
      "limits": [
        {
          "counter": "plot_histogram_1d_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 CERN ROOT MCP Server, so you can run agents against it safely.

FAQ

Questions about plot_histogram_1d

What does the plot_histogram_1d tool do? +

Create and save a 1D histogram plot. Provide EITHER. It is categorised as a Write tool in the CERN ROOT 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 plot_histogram_1d? +

Register the CERN ROOT MCP Server MCP server in PolicyLayer and add a rule for plot_histogram_1d: 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 CERN ROOT MCP Server. Nothing to install.

What risk level is plot_histogram_1d? +

plot_histogram_1d is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit plot_histogram_1d? +

Yes. Add a rate_limit block to the plot_histogram_1d 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 plot_histogram_1d completely? +

Set action: deny in the PolicyLayer policy for plot_histogram_1d. 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 plot_histogram_1d? +

plot_histogram_1d is provided by the CERN ROOT MCP Server MCP server (mohamedelashri/root-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.