Lists active and recent JFR recordings for a Java process (jcmd JFR.check). Returns recording id, duration, state (running/stopped), and filename. Use before stop_profiling to get the correct recordingId.
Part of the Javaperf server.
Free to start. No card required.
AI agents call list_jfr_recordings to retrieve information from Javaperf without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.
Even though list_jfr_recordings only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.
Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.
{
"version": "1",
"default": "deny",
"tools": {
"list_jfr_recordings": {}
}
}See the full Javaperf policy for all 26 tools.
These attack patterns abuse exactly the kind of access list_jfr_recordings gives an agent. Each links to the full case and the policy that stops it:
Other read tools across the catalogue. The same approach applies to each: allow, with a rate cap to control cost.
Lists active and recent JFR recordings for a Java process (jcmd JFR.check). Returns recording id, duration, state (running/stopped), and filename. Use before stop_profiling to get the correct recordingId.. It is categorised as a Read tool in the Javaperf MCP Server, which means it retrieves data without modifying state.
Register the Javaperf MCP server in PolicyLayer and add a rule for list_jfr_recordings: 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.
list_jfr_recordings is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the list_jfr_recordings 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 list_jfr_recordings. 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.
list_jfr_recordings 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.