# list_materials

List built-in filament material profiles (density, cost, temps).

Agent View of the PolicyLayer registry record for `list_materials`. HTML page: https://policylayer.com/tools/kiln/list-materials

## Facts

- Tool: `list_materials`
- Server: Kiln (`codeofaxel/Kiln`) — https://policylayer.com/tools/kiln.md
- Homepage: https://github.com/codeofaxel/Kiln
- Risk category: Read (Low risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Allowed

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

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

## Why list_materials is rated Low

The tool retrieves and queries existing material profile data without modifying, creating, or deleting any information. It has no capability to change printer state or perform physical operations. In the context of 3D printer control, listing material profiles is informational only and presents minimal security risk even if accessed by an untrusted agent.

From the tool's own definition: "Tool description states 'List built-in filament material profiles (density, cost, temps)' — a pure data retrieval operation with no side effects."

## Use case

AI agents call list_materials to retrieve information from Kiln without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Kiln:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "list_materials": {}
  }
}
```

## Other tools on Kiln (401)

- `cancel_print` — Destructive — https://policylayer.com/tools/kiln/cancel-print.md
- `cancel_print_recovery` — Destructive — https://policylayer.com/tools/kiln/cancel-print-recovery.md
- `cancel_print_service_order` — Destructive — https://policylayer.com/tools/kiln/cancel-print-service-order.md
- `cancel_split_plan` — Destructive — https://policylayer.com/tools/kiln/cancel-split-plan.md
- `delete_agent_note` — Destructive — https://policylayer.com/tools/kiln/delete-agent-note.md
- `delete_cached_model` — Destructive — https://policylayer.com/tools/kiln/delete-cached-model.md
- `delete_file` — Destructive — https://policylayer.com/tools/kiln/delete-file.md
- `delete_shipping_profile` — Destructive — https://policylayer.com/tools/kiln/delete-shipping-profile.md
- `fulfillment_cancel` — Destructive — https://policylayer.com/tools/kiln/fulfillment-cancel.md
- `remove_mesh_floating_regions` — Destructive — https://policylayer.com/tools/kiln/remove-mesh-floating-regions.md
- `remove_spool` — Destructive — https://policylayer.com/tools/kiln/remove-spool.md
- `rollback_design_version` — Destructive — https://policylayer.com/tools/kiln/rollback-design-version.md
- `rollback_firmware` — Destructive — https://policylayer.com/tools/kiln/rollback-firmware.md
- `untrust_printer` — Destructive — https://policylayer.com/tools/kiln/untrust-printer.md
- `acquire_printer_lock` — Execute — https://policylayer.com/tools/kiln/acquire-printer-lock.md
- `arrange_parts_on_plate` — Execute — https://policylayer.com/tools/kiln/arrange-parts-on-plate.md
- `auto_arrange_parts_on_plate` — Execute — https://policylayer.com/tools/kiln/auto-arrange-parts-on-plate.md
- `auto_orient_model` — Execute — https://policylayer.com/tools/kiln/auto-orient-model.md
- `await_print_completion` — Execute — https://policylayer.com/tools/kiln/await-print-completion.md
- `boolean_mesh_op` — Execute — https://policylayer.com/tools/kiln/boolean-mesh-op.md
- `calibrate_direct` — Execute — https://policylayer.com/tools/kiln/calibrate-direct.md
- `clear_emergency_stop` — Execute — https://policylayer.com/tools/kiln/clear-emergency-stop.md
- `compile_scad` — Execute — https://policylayer.com/tools/kiln/compile-scad.md
- `complete_print_recovery` — Execute — https://policylayer.com/tools/kiln/complete-print-recovery.md
- `confirm_print_recovery` — Execute — https://policylayer.com/tools/kiln/confirm-print-recovery.md
- `design_to_gcode_pipeline` — Execute — https://policylayer.com/tools/kiln/design-to-gcode-pipeline.md
- `emergency_stop` — Execute — https://policylayer.com/tools/kiln/emergency-stop.md
- `emergency_trip_input` — Execute — https://policylayer.com/tools/kiln/emergency-trip-input.md
- `firmware_resume_print` — Execute — https://policylayer.com/tools/kiln/firmware-resume-print.md
- `force_print_oversize` — Execute — https://policylayer.com/tools/kiln/force-print-oversize.md
- …and 371 more: https://policylayer.com/tools/kiln.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=kiln · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/kiln