Select a time region in the current track(s). Many effects operate on the selection.
AI agents use select_region to create or update resources in AudacityMCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your AudacityMCP environment.
This tool modifies the selection state within Audacity (a UI/session state change), setting the active region for subsequent operations. It does not delete or irreversibly alter audio data, nor does it execute processing itself. It is a reversible session-state modification, fitting the Write category. Severity is low because it only affects the selection cursor, not the audio content itself.
From the tool's definition 'Select a time region in the current track(s). Many effects operate on the selection.'
Documented attack patterns abuse exactly the kind of access select_region gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and AudacityMCP, and nothing reaches the server without passing your rules. This is the rule we recommend for select_region:
{
"version": "1",
"default": "deny",
"tools": {
"select_region": {
"limits": [
{
"counter": "select_region_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}select_region 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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Select a time region in the current track(s). Many effects operate on the selection. It is categorised as a Write tool in the AudacityMCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Audacity MCP server in PolicyLayer and add a rule for select_region: 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 AudacityMCP. Nothing to install.
select_region 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 select_region 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 select_region. 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.
select_region is provided by the Audacity MCP server (xdarkzx/audacity-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 131 AudacityMCP tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
131 AudacityMCP tools catalogued and risk-classified — across an index of 42,500+ MCP servers.