add_hierarchical_label · Kicad MCP: Risk & Policy

WHAT IT DOES

What add_hierarchical_label does on Kicad

AI agents use add_hierarchical_label 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 add_hierarchical_label needs a policy

This tool creates a new hierarchical label in a KiCad schematic, which is a reversible modification of the design document. It does not execute external code, delete data, or move resources. The empty description reduces confidence slightly, but the naming pattern and sibling context strongly indicate a Write category operation.

From the tool's definition Tool name 'add_hierarchical_label' indicates creation of a hierarchical label in KiCad schematic design. Sibling tools like 'add_copper_zone', 'add_global_label', 'add_lib_symbol', 'add_pcb_line', 'add_pcb_text', 'add_power_symbol' are all schema-modification…

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_hierarchical_label Rate-limited

add_hierarchical_label 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": {
    "add_hierarchical_label": {
      "limits": [
        {
          "counter": "add_hierarchical_label_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 add_hierarchical_label

What does the add_hierarchical_label tool do? +

add_hierarchical_label. 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 add_hierarchical_label? +

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

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

Can I rate-limit add_hierarchical_label? +

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

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

add_hierarchical_label 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.