set_fill_color · MCP Figma MCP: Risk & Policy

WHAT IT DOES

What set_fill_color does on MCP Figma

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

WHY IT NEEDS A POLICY

Why set_fill_color needs a policy

This tool modifies design elements by changing their fill color, which is a reversible write operation. It does not delete data (would be Destructive), execute arbitrary code (would be Execute), nor does it involve financial transactions.

From the tool's definition Tool description states 'Set the fill color of a node in Figma' — a modification operation that changes visual properties of design elements.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_fill_color Rate-limited

set_fill_color 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": {
    "set_fill_color": {
      "limits": [
        {
          "counter": "set_fill_color_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 MCP Figma, so you can run agents against it safely.

FAQ

Questions about set_fill_color

What does the set_fill_color tool do? +

Set the fill color of a node in Figma can be TextNode or FrameNode. It is categorised as a Write tool in the MCP Figma MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on set_fill_color? +

Register the MCP Figma MCP server in PolicyLayer and add a rule for set_fill_color: 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 MCP Figma. Nothing to install.

What risk level is set_fill_color? +

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

Can I rate-limit set_fill_color? +

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

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

set_fill_color is provided by the MCP Figma MCP server (yelowflash09/figma_mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.