# modify_trace

Modify an existing trace (change width, layer, or net).

Agent View of the PolicyLayer registry record for `modify_trace`. HTML page: https://policylayer.com/tools/mixelpixx-kicad-mcp-server/modify-trace

## Facts

- Tool: `modify_trace`
- Server: KiCAD-MCP-Server (`mixelpixx/kicad-mcp-server`) — https://policylayer.com/tools/mixelpixx-kicad-mcp-server.md
- Homepage: https://github.com/mixelpixx/KiCAD-MCP-Server
- Risk category: Write (Medium risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Rate-limited

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "modify_trace",
    "arguments": {}
  }
}
```

## Why modify_trace is rated Medium

This tool modifies PCB trace properties (width, layer, net assignments) which are design parameters that can be undone or reverted in KiCAD. It does not delete traces (which would be Destructive), execute code (Execute), or move money (Financial).

From the tool's own definition: "Tool name 'modify_trace' and description state it 'Modify an existing trace (change width, layer, or net)' — this reversibly alters PCB design data without deleting or executing arbitrary operations."

## Use case

AI agents use modify_trace 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.

## Recommended policy (PolicyLayer)

Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches KiCAD-MCP-Server:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "modify_trace": {
      "limits": [
        {
          "counter": "modify_trace_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on KiCAD-MCP-Server (230)

- `clear_board_outline` — Destructive — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/clear-board-outline.md
- `delete_component` — Destructive — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/delete-component.md
- `delete_graphic` — Destructive — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/delete-graphic.md
- `delete_schematic_component` — Destructive — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/delete-schematic-component.md
- `delete_schematic_net_label` — Destructive — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/delete-schematic-net-label.md
- `delete_schematic_wire` — Destructive — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/delete-schematic-wire.md
- `delete_symbol` — Destructive — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/delete-symbol.md
- `delete_trace` — Destructive — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/delete-trace.md
- `discard_or_reload` — Destructive — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/discard-or-reload.md
- `remove_hierarchical_sheet` — Destructive — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/remove-hierarchical-sheet.md
- `remove_library_table_entry` — Destructive — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/remove-library-table-entry.md
- `remove_schematic_component_property` — Destructive — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/remove-schematic-component-property.md
- `autoroute` — Execute — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/autoroute.md
- `export_3d_cli` — Execute — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/export-3d-cli.md
- `export_drill` — Execute — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/export-drill.md
- `launch_kicad_ui` — Execute — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/launch-kicad-ui.md
- `refill_zones` — Execute — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/refill-zones.md
- `run_drc` — Execute — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/run-drc.md
- `run_erc` — Execute — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/run-erc.md
- `batch_list_symbol_pins` — Read — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/batch-list-symbol-pins.md
- `check_clearance` — Read — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/check-clearance.md
- `check_courtyard_overlaps` — Read — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/check-courtyard-overlaps.md
- `check_freerouting` — Read — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/check-freerouting.md
- `check_kicad_ui` — Read — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/check-kicad-ui.md
- `check_placement_clearance` — Read — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/check-placement-clearance.md
- `download_registry_part` — Read — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/download-registry-part.md
- `estimate_airwire_lengths` — Read — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/estimate-airwire-lengths.md
- `export_bom` — Read — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/export-bom.md
- `export_ipc2581` — Read — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/export-ipc2581.md
- `export_ipcd356` — Read — https://policylayer.com/tools/mixelpixx-kicad-mcp-server/export-ipcd356.md
- …and 200 more: https://policylayer.com/tools/mixelpixx-kicad-mcp-server.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=mixelpixx-kicad-mcp-server · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/mixelpixx-kicad-mcp-server