MCPX Metrics
The MCPX server exposes detailed Prometheus metrics about tool calls available at: http://localhost:3000/metrics
tool_call_duration_ms Histogram​
This is a Prometheus histogram that tracks the duration of each tool call in milliseconds.
Labels​
Each metric entry may include one or more labels for filtering and aggregation. Labels are included only if non-empty.
| Label | Description |
|---|---|
tool-name | Name of the tool being called |
error | "true" if the call failed, "false" if successful |
agent | Name of the calling agent or service |
llm (optional) | LLM provider name (if available) |
model (optional) | Model ID used for the request (if available) |
consumer-tag (optional) | The consumer tag for the request (if provided) |
Example Output​
tool_call_duration_ms_bucket{le=“50”,tool-name=“maps_directions”,error=“false”,agent=“mcpx”} 2
tool_call_duration_ms_count{tool-name=“maps_directions”,error=“false”,agent=“mcpx”} 2
tool_call_duration_ms_sum{tool-name=“maps_directions”,error=“false”,agent=“mcpx”} 67`