@zients/line-mcp-server

Push Audio Message

push_audio_message

Send audio messages to LINE users, groups, or rooms by providing an HTTPS M4A URL and duration in milliseconds. Specify target ID or use default.

Instructions

Send an audio message to a LINE user, group, or room.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "originalContentUrl": "<originalContentUrl>",
      "duration": "<duration>"
    },
    "name": "push_audio_message"
  }
}

Input Schema

Name	Required	Description
`to`	No	Target ID — User ID (U…), Group ID (C…), or Room ID (R…). If omitted, falls back to the DEFAULT_UID environment variable.
`duration`	Yes	Audio duration in milliseconds
`originalContentUrl`	Yes	Audio URL (HTTPS, M4A)

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.1Sep 4, 2026

TDQS

A3.6/5.0

Behavior2/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description must disclose behavioral traits. It only says 'send an audio message', which is a write operation, but it does not mention authentication requirements, potential failures, rate limits, or what happens on success. The description is too sparse to be transparent.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single, concise sentence that states the action and target. It is well-structured and front-loaded with the core purpose, with no unnecessary words.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple send operation, the description covers the essential purpose. However, it lacks information about return values (no output schema) and does not mention any side effects or limitations. Given the tool's simplicity, it is mostly complete but could benefit from a note that it is a one-way push without a response.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema already provides 100% coverage of parameter descriptions, including details like the 'to' pattern and fallback to DEFAULT_UID. The description adds no additional parameter semantics, so a baseline score of 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the action: 'Send an audio message' with the target being a LINE user, group, or room. It is specific to audio and distinguishes it from sibling push_message tools like push_text_message or push_image_message.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies use when sending an audio message, but it does not explicitly state when to use this over alternatives or any exclusions. No guidance on prerequisites or context beyond the message type is provided.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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