A good Rust toolchain catches mistakes before taste gets involved.

Rustjar treats tooling as a set of guardrails rather than a badge collection. Cargo commands, Clippy lints, rustfmt settings, cargo deny checks, fuzz targets, and benchmark jobs all need a reason to exist. A team should know what each check protects, when it is allowed to fail, and which warning is a true release blocker.

The strongest tooling notes connect local workflow to CI behavior. If a developer can reproduce the same checks before opening a review, the build system becomes less mysterious. If a dependency policy is written down, crate upgrades stop feeling like archaeology. If benchmarks record variance and hardware context, performance claims become easier to trust.