Why: Host tools need the kernel workspace to register files the step just wrote, and product budgets must stop a step that keeps calling tools. Evidence: go test ./adapters/native/ ./runtime/ -count=1 passed, including the workdir visibility test. Impact: Host tools can read WorkDir from context. MaxToolCalls limits one kernel step when the request budget leaves it unset. Refs: deliverable-quality-system B1 Co-authored-by: Cursor <cursoragent@cursor.com>