symbol_use · SVG Canvas MCP: Risk & Policy

WHAT IT DOES

What symbol_use does on SVG Canvas MCP

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

WHY IT NEEDS A POLICY

Why symbol_use needs a policy

This tool modifies SVG graphics by placing symbols in a canvas, which is a reversible write operation. It does not execute arbitrary code, delete data, or cause financial transactions. The operation is constrained to symbol placement within SVG graphics, making it a standard Write category tool with low severity since changes can be undone through normal editing operations.

From the tool's definition Tool name 'symbol_use' and description indicating placement/usage of defined symbols. The description in Korean '정의된 심볼을 배치합니다' translates to 'places/arranges defined symbols', which is a write operation that creates or modifies SVG content reversibly.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

symbol_use Rate-limited

symbol_use 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": {
    "symbol_use": {
      "limits": [
        {
          "counter": "symbol_use_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 SVG Canvas MCP, so you can run agents against it safely.

FAQ

Questions about symbol_use

What does the symbol_use tool do? +

정의된 심볼을 배치합니다. It is categorised as a Write tool in the SVG Canvas 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 symbol_use? +

Register the SVG Canvas MCP server in PolicyLayer and add a rule for symbol_use: 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 SVG Canvas MCP. Nothing to install.

What risk level is symbol_use? +

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

Can I rate-limit symbol_use? +

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

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

symbol_use is provided by the SVG Canvas MCP server (kim62210/svg-canvas-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.