Constraints are a feature.
Token budgets, required facts, and why a smaller input should still carry the right information.
The budget is a design decision
Every downstream model has practical limits. A context compiler makes those limits part of the specification, allowing a workflow to define its budget before records are assembled. The budget becomes a constraint to test rather than a surprise at the end.
Priorities need to be explicit
A simple truncation can discard the record a workflow depends on. Ranking and packing are different responsibilities: one orders relevance, while the other fits the selected records within a limit. Required-data guards add a check against losing the facts the workflow expects.
Inspect the tradeoff
A useful evaluation looks at both the emitted bundle and the records that were not selected. Teams can adjust specifications, examine guard results, and compare outputs as requirements change. The aim is not merely fewer tokens. It is an input with a deliberate shape.