tool_set_legend · origin- MCP: Risk & Policy

WHAT IT DOES

What tool_set_legend does on origin-MCP

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

WHY IT NEEDS A POLICY

Why tool_set_legend needs a policy

This tool modifies the legend display properties of a plot—toggling visibility, changing position, and updating labels. These are all reversible cosmetic/metadata changes to the visualization. It does not execute code, access external systems, delete data, or cause financial impact. It fits the Write category as a creation/modification action with no permanent side effects.

From the tool's definition Tool description states: 'Show/hide legend, set position (top-right, top-left, bottom-right, bottom-left, center), and custom labels.' These are reversible modifications to visualization properties.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

tool_set_legend Rate-limited

tool_set_legend 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": {
    "tool_set_legend": {
      "limits": [
        {
          "counter": "tool_set_legend_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 origin-MCP, so you can run agents against it safely.

FAQ

Questions about tool_set_legend

What does the tool_set_legend tool do? +

Show/hide legend, set position (top-right, top-left, bottom-right, bottom-left, center), and custom labels. It is categorised as a Write tool in the origin-MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on tool_set_legend? +

Register the origin- MCP server in PolicyLayer and add a rule for tool_set_legend: 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 origin-MCP. Nothing to install.

What risk level is tool_set_legend? +

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

Can I rate-limit tool_set_legend? +

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

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

tool_set_legend is provided by the origin- MCP server (zhang-923-ze/origin-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.