# list_variables

List account variable NAMES (values are write-only — they are injected into proxy calls and container apps, never read back).

Agent View of the PolicyLayer registry record for `list_variables`. HTML page: https://policylayer.com/tools/ai-dataecho-mcp/list-variables

## Facts

- Tool: `list_variables`
- Server: Mcp (`https://dataecho.ai/mcp`) — https://policylayer.com/tools/ai-dataecho-mcp.md
- Homepage: https://github.com/mohocp/dataecho
- Risk category: Read (Low risk)
- Registry record: grade F, identity unverified
- Server auth posture: open
- Server CORS policy: *
- 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_variables",
    "arguments": {}
  }
}
```

## Why list_variables is rated Low

This tool retrieves metadata about variables (their names) without accessing sensitive values. It has no side effects, does not modify or delete data, and does not execute code or trigger external operations. The explicit design that values are write-only and never read back confirms this is a safe information-retrieval action with minimal blast radius if misused by an AI agent.

From the tool's own definition: "Tool description states 'List account variable NAMES' and explicitly notes 'values are write-only — they are injected into proxy calls and container apps, never read back.' The verb 'list' and the retrieval-only nature (names only, no sensitive values)…"

## Use case

AI agents call list_variables to retrieve information from Mcp 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 Mcp:

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

## Other tools on Mcp (25)

- `delete_site` — Destructive — https://policylayer.com/tools/ai-dataecho-mcp/delete-site.md
- `delete_variable` — Destructive — https://policylayer.com/tools/ai-dataecho-mcp/delete-variable.md
- `drive_delete_file` — Destructive — https://policylayer.com/tools/ai-dataecho-mcp/drive-delete-file.md
- `drive_revoke_token` — Destructive — https://policylayer.com/tools/ai-dataecho-mcp/drive-revoke-token.md
- `app_status` — Read — https://policylayer.com/tools/ai-dataecho-mcp/app-status.md
- `drive_history` — Read — https://policylayer.com/tools/ai-dataecho-mcp/drive-history.md
- `drive_list_files` — Read — https://policylayer.com/tools/ai-dataecho-mcp/drive-list-files.md
- `drive_read_file` — Read — https://policylayer.com/tools/ai-dataecho-mcp/drive-read-file.md
- `drive_tokens` — Read — https://policylayer.com/tools/ai-dataecho-mcp/drive-tokens.md
- `get_site` — Read — https://policylayer.com/tools/ai-dataecho-mcp/get-site.md
- `list_drives` — Read — https://policylayer.com/tools/ai-dataecho-mcp/list-drives.md
- `list_sites` — Read — https://policylayer.com/tools/ai-dataecho-mcp/list-sites.md
- `platform_info` — Read — https://policylayer.com/tools/ai-dataecho-mcp/platform-info.md
- `search_sites` — Read — https://policylayer.com/tools/ai-dataecho-mcp/search-sites.md
- `verify_login_code` — Read — https://policylayer.com/tools/ai-dataecho-mcp/verify-login-code.md
- `claim_site` — Write — https://policylayer.com/tools/ai-dataecho-mcp/claim-site.md
- `create_drive` — Write — https://policylayer.com/tools/ai-dataecho-mcp/create-drive.md
- `drive_move_file` — Write — https://policylayer.com/tools/ai-dataecho-mcp/drive-move-file.md
- `drive_restore` — Write — https://policylayer.com/tools/ai-dataecho-mcp/drive-restore.md
- `drive_share` — Write — https://policylayer.com/tools/ai-dataecho-mcp/drive-share.md
- `drive_write_file` — Write — https://policylayer.com/tools/ai-dataecho-mcp/drive-write-file.md
- `publish_site` — Write — https://policylayer.com/tools/ai-dataecho-mcp/publish-site.md
- `request_login_code` — Write — https://policylayer.com/tools/ai-dataecho-mcp/request-login-code.md
- `set_variable` — Write — https://policylayer.com/tools/ai-dataecho-mcp/set-variable.md
- `update_site_metadata` — Write — https://policylayer.com/tools/ai-dataecho-mcp/update-site-metadata.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=ai-dataecho-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/ai-dataecho-mcp