diff --git a/plans/agent-briefings/primitives-loop.md b/plans/agent-briefings/primitives-loop.md
index 02e7dd00..f6a5a67b 100644
--- a/plans/agent-briefings/primitives-loop.md
+++ b/plans/agent-briefings/primitives-loop.md
@@ -88,7 +88,9 @@ Steps:
 - [x] OCaml: distinguish `Integer of int` / `Number of float` in `sx_types.ml`; update all
       arithmetic primitives for float contagion; fix `parse-number`.
       92/92 numeric tower tests pass; 4874 total (394 pre-existing hs-upstream fails unchanged).
-- [ ] Spec: update `spec/primitives.sx` with new predicates + coercions; document contagion rules.
+- [x] Spec: update `spec/primitives.sx` with new predicates + coercions; document contagion rules.
+      Added integer?/float? predicates; updated number? body; / returns "float"; floor/ceil/truncate
+      return "integer"; +/-/* doc float contagion; fixed double-paren params; 4874/394 baseline.
 - [ ] JS bootstrapper: update number representation and arithmetic.
 - [x] Tests: 92 tests in `spec/tests/test-numeric-tower.sx` — int-arithmetic, float-contagion,
       division, predicates, coercions, rounding, parse-number, equality, modulo, min-max, stringify.
@@ -656,6 +658,7 @@ Brief each language's loop agent (or do inline) after rebasing their branch onto
 
 _Newest first._
 
+- 2026-04-26: Phase 2 Spec done — integer?/float? predicates added to spec/primitives.sx; floor/ceil/truncate :returns updated to "integer"; / to "float"; exact->inexact/inexact->exact docs and returns updated; float contagion documented on +/-/*; 4874/394 baseline. Committed 45ec5535.
 - 2026-04-26: Phase 2 OCaml+Tests done — `Integer of int` / `Number of float` in sx_types.ml; float contagion across all arithmetic; floor/truncate/round → Integer; integer?/float?/exact?/inexact?/exact->inexact/inexact->exact; 92/92 numeric tower tests pass; 4874 total (394 pre-existing unchanged). Committed c70bbdeb.
 - 2026-04-26: Phase 1 complete — JS step done. Fixed fundamental lambda binding bug (index-of on arrays returned -1 not NIL, making bind-lambda-params mis-fire &rest branch). Added _lastErrorKont_/hostError/try-catch stubs. 42/42 vector tests pass. 1847 std / 2362 full passing (up from 5). Committed.
 - 2026-04-25: Phase 1 spec step done — all 10 vector primitives in spec/primitives.sx have full :as type annotations, :returns, :doc; make-vector optional fill param added.