Start testing state for the range. Args: user_id: Optional user ID (admin only) Returns: Testing start result
AI agents invoke start_testing to trigger actions in Ludus FastMCP. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.
This tool executes an action that transitions the cyber range into a testing state, which is an operational state change with effects that cannot be predicted without knowing the range configuration. It's not merely reading data (Read) or creating/modifying configuration (Write), but rather triggering an active operational state change in an external system—characteristic of Execute.
From the tool's definition Tool name 'start_testing' and description 'Start testing state for the range' indicate the tool initiates a state transition in a cyber range environment.
Risk signalsAdmin/system-level operation
Documented attack patterns abuse exactly the kind of access start_testing gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Ludus FastMCP, and nothing reaches the server without passing your rules. This is the rule we recommend for start_testing:
{
"version": "1",
"default": "deny",
"tools": {
"start_testing": {
"limits": [
{
"counter": "start_testing_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}start_testing stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Start testing state for the range. Args: user_id: Optional user ID (admin only) Returns: Testing start result. It is categorised as a Execute tool in the Ludus FastMCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Ludus Fast MCP server in PolicyLayer and add a rule for start_testing: 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 Ludus FastMCP. Nothing to install.
start_testing is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the start_testing 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 start_testing. 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.
start_testing is provided by the Ludus Fast MCP server (tjnull/ludus-fastmcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 201 Ludus FastMCP tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
201 Ludus FastMCP tools catalogued and risk-classified — across an index of 42,500+ MCP servers.