# sms_list_numbers

A read tool on the Twilio SMS MCP Server MCP server.

Agent View of the PolicyLayer registry record for `sms_list_numbers`. HTML page: https://policylayer.com/tools/0x-professor-twilio-mcp-server/sms-list-numbers

## Facts

- Tool: `sms_list_numbers`
- Server: Twilio SMS MCP Server (`0x-professor/twilio-mcp-server`) — https://policylayer.com/tools/0x-professor-twilio-mcp-server.md
- Homepage: https://github.com/0x-Professor/Twilio-mcp-server
- 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": "sms_list_numbers",
    "arguments": {}
  }
}
```

## Why sms_list_numbers is rated Low

Based on naming convention and context from sibling tools on the same Twilio SMS server, 'sms_list_numbers' almost certainly retrieves or enumerates phone numbers associated with the account. This is a read operation with no capacity to modify, delete, or execute external operations. Confidence is moderate rather than high because the description is empty and we must infer intent from the name and server context.

From the tool's own definition: "Tool name 'sms_list_numbers' indicates a listing operation. The description is empty, but sibling tools with 'list' in the name (sms_list_inbox, sms_list_sent) strongly suggest this retrieves data without side effects."

## Use case

AI agents call sms_list_numbers to retrieve information from Twilio SMS MCP Server 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 Twilio SMS MCP Server:

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

## Other tools on Twilio SMS MCP Server (15)

- `sms_cancel_scheduled` — Destructive — https://policylayer.com/tools/0x-professor-twilio-mcp-server/sms-cancel-scheduled.md
- `sms_delete_message` — Destructive — https://policylayer.com/tools/0x-professor-twilio-mcp-server/sms-delete-message.md
- `sms_account_info` — Read — https://policylayer.com/tools/0x-professor-twilio-mcp-server/sms-account-info.md
- `sms_format_number` — Read — https://policylayer.com/tools/0x-professor-twilio-mcp-server/sms-format-number.md
- `sms_get_conversation` — Read — https://policylayer.com/tools/0x-professor-twilio-mcp-server/sms-get-conversation.md
- `sms_get_message` — Read — https://policylayer.com/tools/0x-professor-twilio-mcp-server/sms-get-message.md
- `sms_list_inbox` — Read — https://policylayer.com/tools/0x-professor-twilio-mcp-server/sms-list-inbox.md
- `sms_list_sent` — Read — https://policylayer.com/tools/0x-professor-twilio-mcp-server/sms-list-sent.md
- `sms_lookup_number` — Read — https://policylayer.com/tools/0x-professor-twilio-mcp-server/sms-lookup-number.md
- `sms_redact_message` — Read — https://policylayer.com/tools/0x-professor-twilio-mcp-server/sms-redact-message.md
- `sms_usage_stats` — Read — https://policylayer.com/tools/0x-professor-twilio-mcp-server/sms-usage-stats.md
- `sms_mark_read` — Write — https://policylayer.com/tools/0x-professor-twilio-mcp-server/sms-mark-read.md
- `sms_schedule` — Write — https://policylayer.com/tools/0x-professor-twilio-mcp-server/sms-schedule.md
- `sms_send` — Write — https://policylayer.com/tools/0x-professor-twilio-mcp-server/sms-send.md
- `sms_send_bulk` — Write — https://policylayer.com/tools/0x-professor-twilio-mcp-server/sms-send-bulk.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=0x-professor-twilio-mcp-server · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/0x-professor-twilio-mcp-server