vlc-mcp

by jaseonline

Overview Schema Source Related Servers Discussions Admin

Python

Local

select_track

Select a VLC title, chapter, audio, video, or subtitle track by ID, and disable subtitles with -1 to control playback.

Instructions

Select a title, chapter, audio track, video track or subtitle track.

Args: kind: One of title, chapter, audio, video, subtitle track_id: The stream number from get_tracks (or the title/chapter number). Use -1 for subtitle to disable it.

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": {
      "kind": "<kind>",
      "track_id": "<track_id>"
    },
    "name": "select_track"
  }
}

Input Schema

Name	Required	Description	Default
`kind`	Yes
`track_id`	Yes

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Nov 12, 2026

TDQS

A3.9/5.0

Behavior3/5

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

No annotations are supplied, so the description carries the full behavioral burden. It does disclose one real behavior (track_id -1 disables subtitles) and the ID sourcing rule, but says nothing about what happens when an invalid track_id is passed, whether the selection takes effect immediately on playback, or whether it persists.

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?

One summary sentence followed by two tightly scoped argument lines; every clause carries information, and the purpose is front-loaded before the parameter details.

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?

With only two required parameters and an output schema already present, the description supplies what the schema does not. The remaining gap is error behavior for bad track IDs, which matters for a tool that may silently no-op, but otherwise it is sufficient to call correctly.

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

Parameters4/5

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

Schema coverage is 0%, and the Args block fully compensates: it enumerates the five legal values of kind, explains that track_id comes from get_tracks, allows the title/chapter number, and defines the -1 sentinel. Only the exact string spelling of kind values is left implicit.

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

Purpose4/5

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

States a concrete verb (select) plus the five resource types it can target (title, chapter, audio, video, subtitle), which is far more specific than the bare name. It does not explicitly say how it differs from siblings like get_tracks or show_video, so it stops short of 5.

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

Usage Guidelines4/5

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

It points the agent to get_tracks as the source of valid track_id values and gives a concrete special case (-1 disables subtitles). There are no explicit exclusions or failure conditions, but the usage context is clear enough to act on.

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