Starts JFR on the target PID. Rotates recordings (old_profile.jfr ← new_profile.jfr). Default preset is profile. Optional preset or settingsFile (.jfc, cwd-relative or absolute)—mutually exclusive. Builtin presets may omit socket/I/O/native/locks; use a custom .jfc for jdk.SocketRead/Write, FileR...
Part of the Javaperf server.
Free to start. No card required.
AI agents invoke start_profiling to trigger processes or run actions in Javaperf. Execute operations can have side effects beyond the immediate call -- triggering builds, sending notifications, or starting workflows. Rate limits and argument validation are essential to prevent runaway execution.
start_profiling can trigger processes with real-world consequences. An uncontrolled agent might start dozens of builds, send mass notifications, or kick off expensive compute jobs. PolicyLayer enforces rate limits and validates arguments to keep execution within safe bounds.
Execute tools trigger processes. Rate-limit and validate arguments to prevent unintended side effects.
{
"version": "1",
"default": "deny",
"tools": {
"start_profiling": {
"limits": [
{
"counter": "start_profiling_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}See the full Javaperf policy for all 26 tools.
These attack patterns abuse exactly the kind of access start_profiling gives an agent. Each links to the full case and the policy that stops it:
Other execute tools across the catalogue. The same approach applies to each: rate-limit and validate the arguments.
Starts JFR on the target PID. Rotates recordings (old_profile.jfr ← new_profile.jfr). Default preset is profile. Optional preset or settingsFile (.jfc, cwd-relative or absolute)—mutually exclusive. Builtin presets may omit socket/I/O/native/locks; use a custom .jfc for jdk.SocketRead/Write, FileRead/Write, JavaMonitorBlocked, jdk.ThreadPark, NativeMethodSample. Then list_jfr_recordings and stop_profiling.. It is categorised as a Execute tool in the Javaperf MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Javaperf MCP server in PolicyLayer and add a rule for start_profiling: 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 Javaperf. Nothing to install.
start_profiling 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_profiling 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_profiling. 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_profiling is provided by the Javaperf MCP server (javaperf). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 26 Javaperf tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.