<PackageReference Include="Microsoft.Identity.Client" Version="4.85.2" />

Microsoft.Identity.Client.Extensibility.MsalMetricsCatalog

public static class MsalMetricsCatalog
Describes the OpenTelemetry metrics that MSAL emits and, for each metric, the canonical (MSAL-owned) tag names it records. Consumers such as downstream metric pipelines can use CanonicalTagsByMetric to discover which tags belong to a given MSAL metric and, for example, keep only those tags.
public static IReadOnlyDictionary<string, IReadOnlyList<string>> CanonicalTagsByMetric { get; }

Maps each MSAL metric name to the read-only list of canonical tag names that metric records. Keys are compared with Ordinal.