Search and retrieve traces from Mackerel for distributed tracing analysis. 🔍 USE THIS TOOL WHEN USERS: - Search for traces within a time range - Find slow traces by latency filtering - Filter traces by service, environment, or version - Investigate distributed system behavior <examples> Basic tr...
AI agents call list_traces to retrieve information from Mackerel MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
list_traces performs search and retrieval of distributed tracing data from Mackerel. The operations described (searching within time ranges, filtering by service/environment/version, investigating behavior) are all non-destructive queries that retrieve existing monitoring data without creating, modifying, or deleting anything.
From the tool's definition Tool description states 'Search and retrieve traces' and usage examples show 'search for traces', 'find slow traces', 'filter traces' — all read-only query operations with no modification or deletion of data.
Documented attack patterns abuse exactly the kind of access list_traces gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Mackerel MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for list_traces:
{
"version": "1",
"default": "deny",
"tools": {
"list_traces": {}
}
}list_traces is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Search and retrieve traces from Mackerel for distributed tracing analysis. 🔍 USE THIS TOOL WHEN USERS: - Search for traces within a time range - Find slow traces by latency filtering - Filter traces by service, environment, or version - Investigate distributed system behavior <examples> Basic trace search \. It is categorised as a Read tool in the Mackerel MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Mackerel MCP Server MCP server in PolicyLayer and add a rule for list_traces: 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 Mackerel MCP Server. Nothing to install.
list_traces 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_traces 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_traces. 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_traces is provided by the Mackerel MCP Server MCP server (mackerelio-labs/mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Mackerel MCP Server, 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.
16 Mackerel MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.