generate_bar_chart · ECharts MCP Server MCP: Risk & Policy

WHAT IT DOES

What generate_bar_chart does on ECharts MCP Server

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

WHY IT NEEDS A POLICY

Why generate_bar_chart needs a policy

This tool creates a chart preview URL based on provided data. It produces a new artifact (a preview link) but has no destructive, financial, or code execution implications. The blast radius of misuse is minimal — at worst an incorrect or misleading chart is generated.

From the tool's definition Generate a bar chart preview link...which user can click to show data

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

generate_bar_chart Rate-limited

generate_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": {
    "generate_bar_chart": {
      "limits": [
        {
          "counter": "generate_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 ECharts MCP Server, so you can run agents against it safely.

FAQ

Questions about generate_bar_chart

What does the generate_bar_chart tool do? +

Generate a bar chart preview link(not a chart image) which user can click to show data for numerical comparisons among different categories, such as, comparing categorical data and for horizontal comparisons. It is categorised as a Write tool in the ECharts 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 generate_bar_chart? +

Register the ECharts MCP Server MCP server in PolicyLayer and add a rule for generate_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 ECharts MCP Server. Nothing to install.

What risk level is generate_bar_chart? +

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

Can I rate-limit generate_bar_chart? +

Yes. Add a rate_limit block to the generate_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 generate_bar_chart completely? +

Set action: deny in the PolicyLayer policy for generate_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 generate_bar_chart? +

generate_bar_chart is provided by the ECharts MCP Server MCP server (zhr7777777/echarts-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.