Create a named persistent volume. Volumes survive sandbox restarts and can be shared across sandboxes.
AI agents use volume_create to create or update resources in Microsandbox — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Microsandbox environment.
This tool modifies state by creating persistent storage artifacts that remain after sandbox restarts and span multiple sandboxes. This is clearly a write operation—it creates new data structures with lasting effects. While not immediately destructive (volumes can be deleted), the persistent cross-sandbox nature and lack of reversibility guarantees elevate severity to medium.
From the tool's definition Tool creates a persistent volume that survives sandbox restarts and can be shared across sandboxes. The verb 'create' with persistent storage modification indicates write capability. The description explicitly states 'Create a named persistent volume.'
Documented attack patterns abuse exactly the kind of access volume_create gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Microsandbox, and nothing reaches the server without passing your rules. This is the rule we recommend for volume_create:
{
"version": "1",
"default": "deny",
"tools": {
"volume_create": {
"limits": [
{
"counter": "volume_create_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}volume_create 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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Create a named persistent volume. Volumes survive sandbox restarts and can be shared across sandboxes. It is categorised as a Write tool in the Microsandbox MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Microsandbox MCP server in PolicyLayer and add a rule for volume_create: 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 Microsandbox. Nothing to install.
volume_create 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 volume_create 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 volume_create. 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.
volume_create is provided by the Microsandbox MCP server (superradcompany/microsandbox-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Microsandbox, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
19 Microsandbox tools catalogued and risk-classified — across an index of 43,000+ MCP servers.