# ae_add_expression

Add JavaScript expressions to properties for dynamic, code-driven animations

Agent View of the PolicyLayer registry record for `ae_add_expression`. HTML page: https://policylayer.com/tools/ae/ae-add-expression

## Facts

- Tool: `ae_add_expression`
- Server: Ae (`ae-mcp-server`) — https://policylayer.com/tools/ae.md
- Install: `npx -y ae-mcp-server`
- Homepage: https://www.npmjs.com/package/ae-mcp-server
- Risk category: Execute (High 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": "ae_add_expression",
    "arguments": {}
  }
}
```

## Why ae_add_expression is rated High

This tool executes arbitrary JavaScript code within After Effects. An AI agent could inject malicious or unintended JavaScript expressions that run in the AE scripting environment, potentially causing unintended side effects, crashing the application, or executing host-level operations via AE's scripting API. The 'code-driven' nature confirms arbitrary code execution, making this Execute category with high severity.

From the tool's own definition: "Add JavaScript expressions to properties for dynamic, code-driven animations"

## Use case

AI agents invoke ae_add_expression to trigger actions in Ae. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.

## Recommended policy (PolicyLayer)

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

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "ae_add_expression": {
      "limits": [
        {
          "counter": "ae_add_expression_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Ae (34)

- `ae_delete_layer` — Destructive — https://policylayer.com/tools/ae/ae-delete-layer.md
- `ae_remove_effect` — Destructive — https://policylayer.com/tools/ae/ae-remove-effect.md
- `ae_render_preview` — Execute — https://policylayer.com/tools/ae/ae-render-preview.md
- `ae_select_layers` — Execute — https://policylayer.com/tools/ae/ae-select-layers.md
- `ae_check_connection` — Read — https://policylayer.com/tools/ae/ae-check-connection.md
- `ae_get_composition_info` — Read — https://policylayer.com/tools/ae/ae-get-composition-info.md
- `ae_get_effect_info` — Read — https://policylayer.com/tools/ae/ae-get-effect-info.md
- `ae_get_layer_info` — Read — https://policylayer.com/tools/ae/ae-get-layer-info.md
- `ae_get_render_queue_info` — Read — https://policylayer.com/tools/ae/ae-get-render-queue-info.md
- `ae_get_screenshot` — Read — https://policylayer.com/tools/ae/ae-get-screenshot.md
- `mcp_health_check` — Read — https://policylayer.com/tools/ae/mcp-health-check.md
- `mcp_performance_metrics` — Read — https://policylayer.com/tools/ae/mcp-performance-metrics.md
- `mcp_system_diagnostics` — Read — https://policylayer.com/tools/ae/mcp-system-diagnostics.md
- `ae_add_audio_markers` — Write — https://policylayer.com/tools/ae/ae-add-audio-markers.md
- `ae_add_keyframe` — Write — https://policylayer.com/tools/ae/ae-add-keyframe.md
- `ae_add_text_animator` — Write — https://policylayer.com/tools/ae/ae-add-text-animator.md
- `ae_animate_camera` — Write — https://policylayer.com/tools/ae/ae-animate-camera.md
- `ae_animate_property` — Write — https://policylayer.com/tools/ae/ae-animate-property.md
- `ae_apply_color_grading` — Write — https://policylayer.com/tools/ae/ae-apply-color-grading.md
- `ae_apply_effect` — Write — https://policylayer.com/tools/ae/ae-apply-effect.md
- `ae_apply_effect_preset` — Write — https://policylayer.com/tools/ae/ae-apply-effect-preset.md
- `ae_create_composition` — Write — https://policylayer.com/tools/ae/ae-create-composition.md
- `ae_create_layer` — Write — https://policylayer.com/tools/ae/ae-create-layer.md
- `ae_create_null_controller` — Write — https://policylayer.com/tools/ae/ae-create-null-controller.md
- `ae_create_particle_system` — Write — https://policylayer.com/tools/ae/ae-create-particle-system.md
- `ae_duplicate_layer` — Write — https://policylayer.com/tools/ae/ae-duplicate-layer.md
- `ae_enable_motion_blur` — Write — https://policylayer.com/tools/ae/ae-enable-motion-blur.md
- `ae_export_video` — Write — https://policylayer.com/tools/ae/ae-export-video.md
- `ae_import_file` — Write — https://policylayer.com/tools/ae/ae-import-file.md
- `ae_parent_layer` — Write — https://policylayer.com/tools/ae/ae-parent-layer.md
- …and 4 more: https://policylayer.com/tools/ae.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`

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