AI agents use add_schematic_net_label 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.
Adding a schematic net label creates or modifies design data in KiCAD (a PCB/circuit design tool) reversibly. The operation can be undone and does not destroy data or execute arbitrary code. It falls clearly into the Write category. Severity is medium because incorrect net labels could cause design errors leading to circuit malfunctions, but the effect is limited to a single schematic element and is reversible.
From the tool's definition Tool name 'add_schematic_net_label' and description 'Add a net label to the schematic' indicate creation of a new schematic element. This is a create/modify operation that adds a net label to circuit design.
Documented attack patterns abuse exactly the kind of access add_schematic_net_label 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_schematic_net_label:
{
"version": "1",
"default": "deny",
"tools": {
"add_schematic_net_label": {
"limits": [
{
"counter": "add_schematic_net_label_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
} add_schematic_net_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.
Free to start. No card required.
Add a net label to the schematic. 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_schematic_net_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-MCP-Server. Nothing to install.
add_schematic_net_label 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_schematic_net_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.
Set action: deny in the PolicyLayer policy for add_schematic_net_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.
add_schematic_net_label 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.