set_font_size · Claude Talk to Figma MCP: Risk & Policy

WHAT IT DOES

What set_font_size does on Claude Talk to Figma MCP

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

WHY IT NEEDS A POLICY

Why set_font_size needs a policy

This tool creates or modifies design data (font size of text) without irreversible deletion, financial impact, or external code execution. The change is reversible (font size can be changed again), making it a Write operation. The blast radius is low since it only affects styling of a single text element within a design document.

From the tool's definition Tool modifies the font size property of a text node in Figma, which is a reversible change to design elements. The description states it 'Set the font size' indicating a modification operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_font_size Rate-limited

set_font_size 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_font_size": {
      "limits": [
        {
          "counter": "set_font_size_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 Claude Talk to Figma MCP, so you can run agents against it safely.

FAQ

Questions about set_font_size

What does the set_font_size tool do? +

Set the font size of a text node in Figma. It is categorised as a Write tool in the Claude Talk to Figma 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 set_font_size? +

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

What risk level is set_font_size? +

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

Can I rate-limit set_font_size? +

Yes. Add a rate_limit block to the set_font_size 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_font_size completely? +

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

set_font_size is provided by the Claude Talk to Figma MCP server (stranyer/claude-mcp-figma). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.