# set_caption

Set Lightroom caption metadata for selected photos or local_ids.

Agent View of the PolicyLayer registry record for `set_caption`. HTML page: https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/set-caption

## Facts

- Tool: `set_caption`
- Server: Lightroom Classic MCP (`4xiomdev/lightroom-classic-mcp`) — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp.md
- Homepage: https://github.com/4xiomdev/lightroom-classic-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": "set_caption",
    "arguments": {}
  }
}
```

## Why set_caption is rated Medium

This tool creates or modifies caption metadata on photos without deletion or destructive effects. While it mutates catalog state, the change is reversible (captions can be edited, cleared, or reverted). Severity is medium because unintended bulk caption changes could clutter metadata, but the impact is confined to that specific metadata field and easily corrected.

From the tool's own definition: "Tool description states it 'Set[s] Lightroom caption metadata' — a metadata write operation. The tool modifies photo properties (captions) in the Lightroom catalog reversibly, with no deletion or irreversible effects."

## Use case

AI agents use set_caption to create or update resources in Lightroom Classic MCP, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Lightroom Classic MCP environment.

## Recommended policy (PolicyLayer)

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

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

## Other tools on Lightroom Classic MCP (58)

- `delete_collection` — Destructive — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/delete-collection.md
- `delete_snapshot` — Destructive — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/delete-snapshot.md
- `remove_from_collection` — Destructive — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/remove-from-collection.md
- `reset_current_photo` — Destructive — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/reset-current-photo.md
- `auto_tone` — Execute — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/auto-tone.md
- `select_mask_tool` — Execute — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/select-mask-tool.md
- `send_raw_lightroom_command` — Execute — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/send-raw-lightroom-command.md
- `toggle_lens_blur_depth_viz` — Execute — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/toggle-lens-blur-depth-viz.md
- `toggle_mask_overlay` — Execute — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/toggle-mask-overlay.md
- `can_undo` — Read — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/can-undo.md
- `find_photo_by_path` — Read — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/find-photo-by-path.md
- `get_active_photo` — Read — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/get-active-photo.md
- `get_active_photo_file` — Read — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/get-active-photo-file.md
- `get_develop_group_settings` — Read — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/get-develop-group-settings.md
- `get_develop_param_range` — Read — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/get-develop-param-range.md
- `get_develop_settings` — Read — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/get-develop-settings.md
- `get_local_adjustment_settings` — Read — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/get-local-adjustment-settings.md
- `get_selected_photo_files` — Read — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/get-selected-photo-files.md
- `get_selected_photos` — Read — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/get-selected-photos.md
- `lightroom_list_commands` — Read — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/lightroom-list-commands.md
- `lightroom_ping` — Read — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/lightroom-ping.md
- `lightroom_status` — Read — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/lightroom-status.md
- `list_collections` — Read — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/list-collections.md
- `list_develop_groups` — Read — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/list-develop-groups.md
- `list_develop_param_ranges` — Read — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/list-develop-param-ranges.md
- `list_develop_parameters` — Read — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/list-develop-parameters.md
- `list_develop_presets` — Read — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/list-develop-presets.md
- `list_lightroom_presets` — Read — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/list-lightroom-presets.md
- `list_local_params` — Read — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/list-local-params.md
- `list_snapshots` — Read — https://policylayer.com/tools/4xiomdev-lightroom-classic-mcp/list-snapshots.md
- …and 28 more: https://policylayer.com/tools/4xiomdev-lightroom-classic-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=4xiomdev-lightroom-classic-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/4xiomdev-lightroom-classic-mcp