AI agents use replace_schematic_component 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 modifies schematic design by swapping one component for another, altering the circuit design reversibly. It does not create permanent losses (Destructive), execute arbitrary code (Execute), move money (Financial), or merely read data (Read). It falls squarely into Write category as a reversible data modification operation.
From the tool's definition Tool name 'replace_schematic_component' and description 'Replace a placed component' indicate modification of existing schematic design data. The action is reversible—the previous component can be restored via undo or re-replacement.
Documented attack patterns abuse exactly the kind of access replace_schematic_component 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 replace_schematic_component:
{
"version": "1",
"default": "deny",
"tools": {
"replace_schematic_component": {
"limits": [
{
"counter": "replace_schematic_component_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
} replace_schematic_component 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.
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Replace a placed component. 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 replace_schematic_component: 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.
replace_schematic_component 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 replace_schematic_component 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 replace_schematic_component. 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.
replace_schematic_component 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.