create_viz · HoloViz MCP Server MCP: Risk & Policy

WHAT IT DOES

What create_viz does on HoloViz MCP Server

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

WHY IT NEEDS A POLICY

Why create_viz needs a policy

The tool creates new visualization objects within the chat interface. This is a reversible write operation that generates or modifies data (visualization state) but carries minimal severity—visualizations can be regenerated or deleted without consequence.

From the tool's definition Tool name 'create_viz' indicates creation of visualizations; described as enabling creation of 'interactive visualizations' in server description. No destructive, financial, or code-execution keywords present.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_viz Rate-limited

create_viz 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": {
    "create_viz": {
      "limits": [
        {
          "counter": "create_viz_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 HoloViz MCP Server, so you can run agents against it safely.

FAQ

Questions about create_viz

What does the create_viz tool do? +

create_viz. It is categorised as a Write tool in the HoloViz 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 create_viz? +

Register the HoloViz MCP Server MCP server in PolicyLayer and add a rule for create_viz: 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 HoloViz MCP Server. Nothing to install.

What risk level is create_viz? +

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

Can I rate-limit create_viz? +

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

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

create_viz is provided by the HoloViz MCP Server MCP server (sumayabee/holoviz-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.