Add metric description assertions to RPC tests

Co-authored-by: trask <[email protected]>

Author: Copilot

instrumentation-api-incubator/src/test/java/io/opentelemetry/instrumentation/api/incubator/semconv/rpc/RpcClientMetricsTest.java

@@ -80,6 +80,7 @@ void collectsMetrics() {
                 assertThat(metric)
                     .hasName("rpc.client.duration")
                     .hasUnit("ms")
+                    .hasDescription("Measures the duration of outbound RPC.")
                     .hasHistogramSatisfying(
                         histogram ->
                             histogram.hasPointsSatisfying(
@@ -112,6 +113,7 @@ void collectsMetrics() {
                 assertThat(metric)
                     .hasName("rpc.client.duration")
                     .hasUnit("ms")
+                    .hasDescription("Measures the duration of outbound RPC.")
                     .hasHistogramSatisfying(
                         histogram ->
                             histogram.hasPointsSatisfying(

instrumentation-api-incubator/src/test/java/io/opentelemetry/instrumentation/api/incubator/semconv/rpc/RpcServerMetricsTest.java

@@ -82,6 +82,7 @@ void collectsMetrics() {
                 assertThat(metric)
                     .hasName("rpc.server.duration")
                     .hasUnit("ms")
+                    .hasDescription("Measures the duration of inbound RPC.")
                     .hasHistogramSatisfying(
                         histogram ->
                             histogram.hasPointsSatisfying(
@@ -113,6 +114,7 @@ void collectsMetrics() {
                 assertThat(metric)
                     .hasName("rpc.server.duration")
                     .hasUnit("ms")
+                    .hasDescription("Measures the duration of inbound RPC.")
                     .hasHistogramSatisfying(
                         histogram ->
                             histogram.hasPointsSatisfying(