EF Core’s entity discovery is thorough by design. In a plugin architecture, that thoroughness becomes a liability: navigation properties pull plugin entities into the host migration, creating shared schema ownership that breaks plugin isolation, causes schema drift, and makes clean plugin uninstalls impossible.
MCP is JSON-RPC with conventions, not magic. This guide builds a Model Context Protocol server in .NET with the official SDK: stdio and Streamable HTTP transports, tightly-scoped typed tools, JWT authentication, prompt-injection defenses, OpenTelemetry tracing, and the production failure modes the demos never mention.
Every pattern here addresses a failure mode I have either shipped or inherited. Source generators on hot paths, scope opt-in per provider, end-to-end correlation ID propagation, log levels as an ops contract, sink selection as an architecture decision, and OpenTelemetry Logs for greenfield services: six concrete changes that make structured logging trustworthy in production.
FakeTimeProvider gives you a clock you control. That solves the easy 30%.
The hard part is everything that interacts with that clock: async callbacks,
PeriodicTimer, CancellationTokenSource.CancelAfter, BackgroundService loops,
and DI lifetime traps that turn deterministic bugs into apparently flaky tests.
Directory.Build.props drift is the quiet tax every multi-repo .NET org pays. NetEvolve.Defaults ships MSBuild properties, .editorconfig, NuGet Audit, and ten Roslyn diagnostics as a private-asset NuGet package. Bump the version once, every repo gets the upgrade.
