Increase or decrease the volume by a specified percentage.
AI agents use adjust_volume to create or update resources in Vlc — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Vlc environment.
This tool modifies a media player setting (volume level) which is a reversible write operation. It has minimal blast radius as it only affects local audio output and can be easily changed back. No data is deleted, no code is executed, and no financial transactions occur.
From the tool's definition 'Increase or decrease the volume by a specified percentage' — modifies the volume state of the VLC media player
Documented attack patterns abuse exactly the kind of access adjust_volume gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Vlc, and nothing reaches the server without passing your rules. This is the rule we recommend for adjust_volume:
{
"version": "1",
"default": "deny",
"tools": {
"adjust_volume": {
"limits": [
{
"counter": "adjust_volume_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}adjust_volume 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.
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Increase or decrease the volume by a specified percentage. It is categorised as a Write tool in the Vlc MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Vlc MCP server in PolicyLayer and add a rule for adjust_volume: 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 Vlc. Nothing to install.
adjust_volume is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the adjust_volume 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.
Set action: deny in the PolicyLayer policy for adjust_volume. 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.
adjust_volume is provided by the Vlc MCP server (piebro/vlc-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Vlc, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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8 Vlc tools catalogued and risk-classified — across an index of 43,000+ MCP servers.