create_sym_lib_table · Kicad MCP: Risk & Policy

WHAT IT DOES

What create_sym_lib_table does on Kicad

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

WHY IT NEEDS A POLICY

Why create_sym_lib_table needs a policy

Creating a symbol library table is a reversible modification to KiCad project configuration. It adds or configures a data structure but does not delete data, execute arbitrary code, or cause financial impact. The blast radius is medium because incorrect symbol library configuration could cause design issues or project corruption, but the operation itself is non-destructive and can be undone or reconfigured.

From the tool's definition Tool name 'create_sym_lib_table' indicates creation of a symbol library table. The sibling tools include 'add_lib_symbol', 'add_pcb_line', 'add_pcb_text', and other additive operations, establishing this as a Write-class server.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_sym_lib_table Rate-limited

create_sym_lib_table 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": {
    "create_sym_lib_table": {
      "limits": [
        {
          "counter": "create_sym_lib_table_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 Kicad, so you can run agents against it safely.

FAQ

Questions about create_sym_lib_table

What does the create_sym_lib_table tool do? +

create_sym_lib_table. It is categorised as a Write tool in the Kicad MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_sym_lib_table? +

Register the Kicad MCP server in PolicyLayer and add a rule for create_sym_lib_table: 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 create_sym_lib_table? +

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

Can I rate-limit create_sym_lib_table? +

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

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

create_sym_lib_table 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.