Built an open-source SQL diagnostics tool — paste any query, get severity-ranked findings with dialect-correct DDL across 5 databases. No DB connection needed.

New: findings are labelled with three evidence tiers:
Deterministic — always applies regardless of data
Schema-verified — verified against your DDL
Estimated — pattern-based, verify with EXPLAIN

<https://querytuner.com/> — free, no signup
<https://github.com/AutoShiftOps/querytuner>

Especially curious whether the evidence labelling is useful or confusing to real users.