fit_histogram · CERN ROOT MCP Server MCP: Risk & Policy

WHAT IT DOES

What fit_histogram does on CERN ROOT MCP Server

AI agents invoke fit_histogram to trigger actions in CERN ROOT MCP Server. 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 fit_histogram needs a policy

Fitting a histogram with a model function involves executing a computational process (numerical optimization/fitting algorithm) on data. It doesn't merely read data passively, but triggers an external computation whose results depend on the arguments (model function, fit parameters, data). No data is permanently modified or deleted, and no financial operations occur, so Execute is the most appropriate category.

From the tool's definition 'fit_histogram' — 'Fit histogram with model function' implies running a numerical fitting algorithm/computation against data

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

fit_histogram Rate-limited

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

FAQ

Questions about fit_histogram

What does the fit_histogram tool do? +

Fit histogram with model function. It is categorised as a Execute tool in the CERN ROOT MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on fit_histogram? +

Register the CERN ROOT MCP Server MCP server in PolicyLayer and add a rule for fit_histogram: 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 fit_histogram? +

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

Can I rate-limit fit_histogram? +

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

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

fit_histogram 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.