Place a mounting hole (NPTH or PTH) at the specified position on the PCB.
AI agents use add_mounting_hole to create or update resources in KiCAD-MCP-Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your KiCAD-MCP-Server environment.
This tool creates a new mounting hole feature on a PCB, which is a reversible modification to the design. It does not execute arbitrary code, delete data irreversibly, or move money. The action is a design creation/write operation. Severity is medium because incorrect placement could require board redesign, but the change can be undone in the design software.
From the tool's definition Tool name 'add_mounting_hole' and description 'Place a mounting hole (NPTH or PTH) at the specified position on the PCB' indicate creation of a new PCB design element that modifies the board layout.
Documented attack patterns abuse exactly the kind of access add_mounting_hole gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and KiCAD-MCP-Server, and nothing reaches the server without passing your rules. This is the rule we recommend for add_mounting_hole:
{
"version": "1",
"default": "deny",
"tools": {
"add_mounting_hole": {
"limits": [
{
"counter": "add_mounting_hole_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
} add_mounting_hole 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.
Free to start. No card required.
Place a mounting hole (NPTH or PTH) at the specified position on the PCB. It is categorised as a Write tool in the KiCAD-MCP-Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the KiCAD-MCP-Server MCP server in PolicyLayer and add a rule for add_mounting_hole: 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-MCP-Server. Nothing to install.
add_mounting_hole is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the add_mounting_hole 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.
Set action: deny in the PolicyLayer policy for add_mounting_hole. 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.
add_mounting_hole is provided by the KiCAD-MCP-Server MCP server (mixelpixx/kicad-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from KiCAD-MCP-Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
157 KiCAD-MCP-Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.