create_bar_chart · ContextForge MCP Gateway MCP

WHAT IT DOES

What create_bar_chart does on ContextForge MCP Gateway

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

WHY IT NEEDS A POLICY

Why create_bar_chart needs a policy

The tool creates (generates) a new chart artifact, which is a reversible Write operation. It modifies the document or visualization state by adding a new chart, but the action is non-destructive and can be undone. The blast radius is minimal—misuse would result in unwanted charts being added, not data loss or system compromise. No execution of arbitrary code, deletion, or financial impact is evident.

From the tool's definition Tool name 'create_bar_chart' and description 'Create bar chart for categorical data' indicate creation of a data visualization object.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_bar_chart Rate-limited

create_bar_chart 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_bar_chart": {
      "limits": [
        {
          "counter": "create_bar_chart_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 ContextForge MCP Gateway, so you can run agents against it safely.

FAQ

Questions about create_bar_chart

What does the create_bar_chart tool do? +

Create bar chart for categorical data. It is categorised as a Write tool in the ContextForge MCP Gateway 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_bar_chart? +

Register the ContextForge MCP Gateway MCP server in PolicyLayer and add a rule for create_bar_chart: 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 ContextForge MCP Gateway. Nothing to install.

What risk level is create_bar_chart? +

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

Can I rate-limit create_bar_chart? +

Yes. Add a rate_limit block to the create_bar_chart 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_bar_chart completely? +

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

create_bar_chart is provided by the ContextForge MCP Gateway MCP server (jrmatherly/mcp-context-forge). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.