Define readiness in your terms
Different systems fail in different ways. Expressions let you describe how source signals and dependency status contribute to a node, instead of forcing every device into a single severity scale.
Follow the calculation
A score is useful when you can explain it. Inspect the inputs and expression behind a node, then follow its dependencies to understand what moved the result.
Keep human intent visible
Review model logic as a shared operational definition. Test representative healthy, degraded, missing, and stale inputs before promoting a change.
Get a proposed expression with validation evidence
Ask the Model Agent to recommend an expression using the authorized signal catalog, declared types and units, and relevant model-authoring skills. Inspect the exact Tengo source and the input keys it references.
The runtime can compile and evaluate the proposed source against a pinned current snapshot without changing live state. Its validation receipt describes the tested inputs and limitations. Passing this check does not establish calibrated risk thresholds or prove future behavior under untested conditions.