# evaluate_expression

A execute tool on the Aos MCP server.

Agent View of the PolicyLayer registry record for `evaluate_expression`. HTML page: https://policylayer.com/tools/hybridlabor-api-aos/evaluate-expression

## Facts

- Tool: `evaluate_expression`
- Server: Aos (`@hybridlabor-api/aos`) — https://policylayer.com/tools/hybridlabor-api-aos.md
- Install: `npx -y @hybridlabor-api/aos`
- Homepage: git+https://github.com/hybridlabor-api/aos.git
- 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": "evaluate_expression",
    "arguments": {}
  }
}
```

## Why evaluate_expression is rated High

The name 'evaluate_expression' strongly implies execution of an arbitrary mathematical expression, which may permit execution of unintended or complex computations. Since the description is empty, exact behavior is unknown, but sibling tools suggest this evaluates math expressions. The execute category fits best given the potential for arbitrary expression evaluation.

From the tool's own definition: "Tool name 'evaluate_expression' on a math server; description is empty and uninformative."

## Use case

AI agents invoke evaluate_expression to trigger actions in Aos. 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 Aos:

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

## Other tools on Aos (718)

- `archive_project` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/archive-project.md
- `clear_clip_flags` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/clear-clip-flags.md
- `clear_layer` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/clear-layer.md
- `close_window` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/close-window.md
- `delete_clip_markers` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/delete-clip-markers.md
- `delete_color_group` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/delete-color-group.md
- `delete_color_version` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/delete-color-version.md
- `delete_face` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/delete-face.md
- `delete_fusion_comp_on_clip` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/delete-fusion-comp-on-clip.md
- `delete_layer` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/delete-layer.md
- `delete_markers` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/delete-markers.md
- `delete_media_pool_clips` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/delete-media-pool-clips.md
- `delete_objects` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/delete-objects.md
- `delete_project` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/delete-project.md
- `delete_render_job` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/delete-render-job.md
- `delete_stills` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/delete-stills.md
- `delete_take` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/delete-take.md
- `delete_td_node` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/delete-td-node.md
- `delete_timeline_clips` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/delete-timeline-clips.md
- `delete_track` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/delete-track.md
- `manage_checkpoint` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/manage-checkpoint.md
- `remoteos_manage_instance` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/remoteos-manage-instance.md
- `remove_background_clip` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/remove-background-clip.md
- `repair_network` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/repair-network.md
- `reset_all_grades` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/reset-all-grades.md
- `unlink_media_pool_clips` — Destructive — https://policylayer.com/tools/hybridlabor-api-aos/unlink-media-pool-clips.md
- `add_render_job` — Execute — https://policylayer.com/tools/hybridlabor-api-aos/add-render-job.md
- `ae_render_active_comp` — Execute — https://policylayer.com/tools/hybridlabor-api-aos/ae-render-active-comp.md
- `apply_glsl_top_mapping` — Execute — https://policylayer.com/tools/hybridlabor-api-aos/apply-glsl-top-mapping.md
- `apply_transform` — Execute — https://policylayer.com/tools/hybridlabor-api-aos/apply-transform.md
- …and 688 more: https://policylayer.com/tools/hybridlabor-api-aos.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=hybridlabor-api-aos · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/hybridlabor-api-aos