Medium Risk

line_send_message

Send any LINE message to any target. Picks the right LINE API automatically (reply / push / multicast / narrowcast / broadcast) based on the shape of \

How to control line_send_message ↓

AI agents use line_send_message to create or update resources in Line Oa Mcp Ultimate — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Line Oa Mcp Ultimate environment.

Medium Risk

This tool creates and sends messages to LINE users, which is a reversible write operation (messages can be deleted or edited after sending in most messaging contexts, though some delivery effects are permanent). While it has significant blast radius due to potential spam or unauthorized communications at scale via broadcast/multicast to many users, it does not delete data (Destructive) or move money (Financial).

From the tool's definition Tool description states 'Send any LINE message to any target' and 'Picks the right LINE API automatically (reply / push / multicast / narrowcast / broadcast)' — these are message transmission operations that create/modify user-facing communications.

Documented attack patterns abuse exactly the kind of access line_send_message gives an agent:

PolicyLayer is an MCP gateway — it sits between your AI agents and Line Oa Mcp Ultimate, and nothing reaches the server without passing your rules. This is the rule we recommend for line_send_message:

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "line_send_message": {
      "limits": [
        {
          "counter": "line_send_message_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

line_send_message stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

  1. Create a free account and register Line Oa Mcp Ultimate — nothing to install.
  2. Add this policy — paste it, or build it visually.
  3. Point your MCP client (Claude, Cursor, anything) at your gateway URL.
LIMIT THIS TOOL →

Free to start. No card required.

Go deeper

What does the line_send_message tool do? +

Send any LINE message to any target. Picks the right LINE API automatically (reply / push / multicast / narrowcast / broadcast) based on the shape of \. It is categorised as a Write tool in the Line Oa Mcp Ultimate MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on line_send_message? +

Register the Line Oa Mcp Ultimate MCP server in PolicyLayer and add a rule for line_send_message: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Line Oa Mcp Ultimate. Nothing to install.

What risk level is line_send_message? +

line_send_message is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit line_send_message? +

Yes. Add a rate_limit block to the line_send_message rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block line_send_message completely? +

Set action: deny in the PolicyLayer policy for line_send_message. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides line_send_message? +

line_send_message is provided by the Line Oa Mcp Ultimate MCP server (wasintoh/line-oa-mcp-ultimate). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Line Oa Mcp Ultimate tool call.

Deterministic rules across all 34 Line Oa Mcp Ultimate tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.

Free to start. No card required.

34 Line Oa Mcp Ultimate tools catalogued and risk-classified — across an index of 42,500+ MCP servers.

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