# unload_xref

卸载外部参照（保留链接但不加载，提高性能）。

Agent View of the PolicyLayer registry record for `unload_xref`. HTML page: https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/unload-xref

## Facts

- Tool: `unload_xref`
- Server: Pypi:best Cad (`pypi:best-cad-mcp`) — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp.md
- Install: `npx -y pypi:best-cad-mcp`
- Homepage: https://github.com/LokmenoWer/best-cad-mcp
- 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": "unload_xref",
    "arguments": {}
  }
}
```

## Why unload_xref is rated Medium

The tool modifies drawing state by unloading external references—a reversible operation that changes how the drawing loads resources without permanently deleting data or executing arbitrary code. This qualifies as Write rather than Destructive because the link is retained and the action can be undone by reloading the xref.

From the tool's own definition: "unload_xref: 卸载外部参照（保留链接但不加载，提高性能）translates to 'unload external reference (retains link but does not load, improves performance)'. This modifies the state of external references in a CAD drawing by changing their load status."

## Use case

AI agents use unload_xref to create or update resources in Pypi:best Cad, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Pypi:best Cad environment.

## Recommended policy (PolicyLayer)

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

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

## Other tools on Pypi:best Cad (320)

- `clear_spatial_annotations` — Destructive — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/clear-spatial-annotations.md
- `clear_understanding_cache` — Destructive — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/clear-understanding-cache.md
- `delete_entities` — Destructive — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/delete-entities.md
- `delete_entity` — Destructive — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/delete-entity.md
- `delete_layer` — Destructive — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/delete-layer.md
- `delete_named_view` — Destructive — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/delete-named-view.md
- `delete_selection_set` — Destructive — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/delete-selection-set.md
- `erase_selection_entities` — Destructive — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/erase-selection-entities.md
- `purge_drawing` — Destructive — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/purge-drawing.md
- `remove_hyperlink` — Destructive — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/remove-hyperlink.md
- `build_drawing_ir` — Execute — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/build-drawing-ir.md
- `check_runtime_environment` — Execute — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/check-runtime-environment.md
- `execute_cad_plan` — Execute — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/execute-cad-plan.md
- `execute_query` — Execute — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/execute-query.md
- `execute_sql_query` — Execute — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/execute-sql-query.md
- `highlight_entities` — Execute — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/highlight-entities.md
- `pan` — Execute — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/pan.md
- `plot_preview` — Execute — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/plot-preview.md
- `plot_to_device` — Execute — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/plot-to-device.md
- `regen` — Execute — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/regen.md
- `reload_xref` — Execute — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/reload-xref.md
- `render_drawing_view` — Execute — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/render-drawing-view.md
- `restart_mcp` — Execute — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/restart-mcp.md
- `restore_named_view` — Execute — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/restore-named-view.md
- `revolve_region` — Execute — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/revolve-region.md
- `select_on_screen` — Execute — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/select-on-screen.md
- `send_command` — Execute — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/send-command.md
- `set_active_layout` — Execute — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/set-active-layout.md
- `set_active_ucs` — Execute — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/set-active-ucs.md
- `set_variable` — Execute — https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp/set-variable.md
- …and 290 more: https://policylayer.com/tools/io-github-lokmenower-best-cad-mcp.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=io-github-lokmenower-best-cad-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/io-github-lokmenower-best-cad-mcp