feat: Add otel spans to tool calls

go.mod

@@ -20,6 +20,9 @@ require (
 	github.com/prometheus/common v0.65.0
 	github.com/prometheus/prometheus v0.305.0
 	github.com/stretchr/testify v1.10.0
+	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.61.0
+	go.opentelemetry.io/otel v1.36.0
+	go.opentelemetry.io/otel/sdk v1.36.0
 )
 
 require (
@@ -37,6 +40,7 @@ require (
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
 	github.com/elazarl/goproxy v1.7.2 // indirect
 	github.com/fatih/color v1.18.0 // indirect
+	github.com/felixge/httpsnoop v1.0.4 // indirect
 	github.com/getkin/kin-openapi v0.132.0 // indirect
 	github.com/go-logr/logr v1.4.2 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
@@ -117,11 +121,9 @@ require (
 	go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptrace v0.61.0 // indirect
 	go.opentelemetry.io/contrib/propagators/jaeger v1.36.0 // indirect
 	go.opentelemetry.io/contrib/samplers/jaegerremote v0.30.0 // indirect
-	go.opentelemetry.io/otel v1.36.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.36.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.36.0 // indirect
 	go.opentelemetry.io/otel/metric v1.36.0 // indirect
-	go.opentelemetry.io/otel/sdk v1.36.0 // indirect
 	go.opentelemetry.io/otel/trace v1.36.0 // indirect
 	go.opentelemetry.io/proto/otlp v1.6.0 // indirect
 	golang.org/x/exp v0.0.0-20250106191152-7588d65b2ba8 // indirect

go.sum

@@ -318,8 +318,8 @@ go.opentelemetry.io/otel/metric v1.36.0/go.mod h1:zC7Ks+yeyJt4xig9DEw9kuUFe5C3zL
 go.opentelemetry.io/otel/sdk v1.21.0/go.mod h1:Nna6Yv7PWTdgJHVRD9hIYywQBRx7pbox6nwBnZIxl/E=
 go.opentelemetry.io/otel/sdk v1.36.0 h1:b6SYIuLRs88ztox4EyrvRti80uXIFy+Sqzoh9kFULbs=
 go.opentelemetry.io/otel/sdk v1.36.0/go.mod h1:+lC+mTgD+MUWfjJubi2vvXWcVxyr9rmlshZni72pXeY=
-go.opentelemetry.io/otel/sdk/metric v1.35.0 h1:1RriWBmCKgkeHEhM7a2uMjMUfP7MsOF5JpUCaEqEI9o=
-go.opentelemetry.io/otel/sdk/metric v1.35.0/go.mod h1:is6XYCUMpcKi+ZsOvfluY5YstFnhW0BidkR+gL+qN+w=
+go.opentelemetry.io/otel/sdk/metric v1.36.0 h1:r0ntwwGosWGaa0CrSt8cuNuTcccMXERFwHX4dThiPis=
+go.opentelemetry.io/otel/sdk/metric v1.36.0/go.mod h1:qTNOhFDfKRwX0yXOqJYegL5WRaW376QbB7P4Pb0qva4=
 go.opentelemetry.io/otel/trace v1.21.0/go.mod h1:LGbsEB0f9LGjN+OZaQQ26sohbOmiMR+BaslueVtS/qQ=
 go.opentelemetry.io/otel/trace v1.36.0 h1:ahxWNuqZjpdiFAyrIoQ4GIiAIhxAunQR6MUoKrsNd4w=
 go.opentelemetry.io/otel/trace v1.36.0/go.mod h1:gQ+OnDZzrybY4k4seLzPAWNwVBBVlF2szhehOBB/tGA=

mcpgrafana.go

@@ -9,12 +9,14 @@ import (
 	"net/http"
 	"net/url"
 	"os"
+	"reflect"
 	"strings"
 
 	"github.com/go-openapi/strfmt"
 	"github.com/grafana/grafana-openapi-client-go/client"
 	"github.com/grafana/incident-go"
 	"github.com/mark3labs/mcp-go/server"
+	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
 )
 
 const (
@@ -56,6 +58,13 @@ type GrafanaConfig struct {
 	// Debug enables debug mode for the Grafana client.
 	Debug bool
 
+	// IncludeArgumentsInSpans enables logging of tool arguments in OpenTelemetry spans.
+	// This should only be enabled in non-production environments or when you're certain 
+	// the arguments don't contain PII. Defaults to false for safety.
+	// Note: OpenTelemetry spans are always created for context propagation, but arguments
+	// are only included when this flag is enabled.
+	IncludeArgumentsInSpans bool
+
 	// URL is the URL of the Grafana instance.
 	URL string
 
@@ -261,7 +270,26 @@ func NewGrafanaClient(ctx context.Context, grafanaURL, apiKey string) *client.Gr
 	}
 
 	slog.Debug("Creating Grafana client", "url", parsedURL.Redacted(), "api_key_set", apiKey != "")
-	return client.NewHTTPClientWithConfig(strfmt.Default, cfg)
+	grafanaClient := client.NewHTTPClientWithConfig(strfmt.Default, cfg)
+
+	// Always enable HTTP tracing for context propagation (no-op when no exporter configured)
+	// Use reflection to wrap the transport without importing the runtime client package
+	v := reflect.ValueOf(grafanaClient.Transport)
+	if v.Kind() == reflect.Ptr && !v.IsNil() {
+		v = v.Elem()
+		if v.Kind() == reflect.Struct {
+			transportField := v.FieldByName("Transport")
+			if transportField.IsValid() && transportField.CanSet() {
+				if rt, ok := transportField.Interface().(http.RoundTripper); ok {
+					wrapped := otelhttp.NewTransport(rt)
+					transportField.Set(reflect.ValueOf(wrapped))
+					slog.Debug("HTTP tracing enabled for Grafana client")
+				}
+			}
+		}
+	}
+
+	return grafanaClient
 }
 
 // ExtractGrafanaClientFromEnv is a StdioContextFunc that extracts Grafana configuration