run_erc · Kicad MCP: Risk & Policy

WHAT IT DOES

What run_erc does on Kicad

AI agents invoke run_erc to trigger actions in Kicad. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why run_erc needs a policy

ERC (Electrical Rules Check) is an analysis/validation operation that executes against a schematic to identify design violations and issues. While it performs a check rather than creating/modifying data (which would be Write), it is fundamentally an Execute action—it runs a diagnostic operation whose output depends on the schematic state.

From the tool's definition Tool name 'run_erc' indicates execution of ERC (Electrical Rules Check) analysis in KiCad. The server description emphasizes 'automation' and 'analysis' capabilities. ERC is a diagnostic operation that analyzes schematic designs but does not modify data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

run_erc Rate-limited

run_erc stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "run_erc": {
      "limits": [
        {
          "counter": "run_erc_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Kicad, so you can run agents against it safely.

FAQ

Questions about run_erc

What does the run_erc tool do? +

run_erc. It is categorised as a Execute tool in the Kicad MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on run_erc? +

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

What risk level is run_erc? +

run_erc is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit run_erc? +

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

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

run_erc is provided by the Kicad MCP server (productofamerica/mcp-server-kicad). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.