diff --git a/src/scribe/mcp/tools/family.py b/src/scribe/mcp/tools/family.py
index 8df85f05..206ad917 100644
--- a/src/scribe/mcp/tools/family.py
+++ b/src/scribe/mcp/tools/family.py
@@ -253,7 +253,6 @@ async def assess_family_adoption(
     reason: str,
     evidence: list[str] | None = None,
     precedent_ids: list[int] | None = None,
-    system_ids: list[int] | None = None,
 ) -> dict:
     """Answer one canon family idea for one project. YOU decide; nobody
     approves. Judge in this order and stop at the first that holds:
@@ -268,8 +267,10 @@ async def assess_family_adoption(
     3. adopted — it applies and the project does it. `evidence` names where
        (a file, a commit, a task, a CI run).
     4. owed — none of the above. A task is filed in THIS project naming the
-       gap and the reference implementation for its language. Nothing edits
-       another repository; the project picks the task up itself.
+       gap and the reference implementation for its language, filed under
+       the project's System matching the idea's area (retag it with
+       update_task if that guess is wrong). Nothing edits another
+       repository; the project picks the task up itself.
 
     Read get_family_adoption first: answer consistently with its precedents
     unless this project differs in a way you can name in `reason`. The
@@ -286,11 +287,10 @@ async def assess_family_adoption(
         reason: why — required for every outcome.
         evidence: where it is done (required for adopted), or what you checked.
         precedent_ids: earlier family decisions you followed, if any.
-        system_ids: Systems for an owed task. Omit to match the idea's own.
     """
     return await adoption_svc.assess(
         current_user_id(), project_id, idea_id, outcome=outcome, reason=reason,
-        evidence=evidence, precedent_ids=precedent_ids, system_ids=system_ids,
+        evidence=evidence, precedent_ids=precedent_ids,
     )
 
 
diff --git a/src/scribe/services/family_adoption.py b/src/scribe/services/family_adoption.py
index 72c6617f..493e9656 100644
--- a/src/scribe/services/family_adoption.py
+++ b/src/scribe/services/family_adoption.py
@@ -519,8 +519,7 @@ async def _matching_systems(session, project_id: int, note_ids: list[int]) -> li
     return list(dict.fromkeys(direct + list(mapped)))
 
 
-async def _file_owed_task(user_id: int, row_id: int, reason: str,
-                          system_ids: list[int] | None) -> Note:
+async def _file_owed_task(user_id: int, row_id: int, reason: str) -> Note:
     from scribe.services import notes as notes_svc
     from scribe.services import systems as systems_svc
 
@@ -531,7 +530,7 @@ async def _file_owed_task(user_id: int, row_id: int, reason: str,
         refs = await _references(session, row.idea_id)
         langs = await _project_languages(session, row.project_id)
         platforms = await family_svc._platform_slugs(session, row.idea_id)
-        systems = system_ids or await _matching_systems(
+        systems = await _matching_systems(
             session, row.project_id, [row.idea_id] + [r["id"] for r in refs])
         project_id, idea_id, version = row.project_id, row.idea_id, idea.canon_version
     body = (
@@ -568,8 +567,7 @@ async def _set_task_status(user_id: int, task: Note, status: str, log: str) -> N
     await task_logs.create_log(user_id, task.id, log)
 
 
-async def _sync_owed_task(user_id: int, row_id: int, *, reason: str,
-                          system_ids: list[int] | None = None) -> dict | None:
+async def _sync_owed_task(user_id: int, row_id: int, *, reason: str) -> dict | None:
     """Make the owed task agree with the answer. Idempotent: an `owed` row
     with an open task, or a settled row with a closed one, is left alone.
     A task the caller cannot write is left alone too, and said so."""
@@ -594,7 +592,7 @@ async def _sync_owed_task(user_id: int, row_id: int, *, reason: str,
                 user_id, task, TaskStatus.todo.value,
                 f"Reopened: family idea #{idea_id} was assessed owed again — {reason}")
             return ref(task, TaskStatus.todo.value, "reopened")
-        task = await _file_owed_task(user_id, row_id, reason, system_ids)
+        task = await _file_owed_task(user_id, row_id, reason)
         async with async_session() as session:
             row = await session.get(FamilyAdoption, row_id)
             row.owed_task_id = task.id
@@ -645,7 +643,7 @@ def _answer(row: FamilyAdoption, *, status: str, reason: str, version: int,
 async def assess(
     user_id: int, project_id: int, idea_id: int, *, outcome: str, reason: str,
     evidence: list[str] | None = None, precedent_ids: list[int] | None = None,
-    system_ids: list[int] | None = None, decided_via: str = "agent",
+    decided_via: str = "agent",
 ) -> dict:
     """Record one project's answer to one canon idea.
 
@@ -692,7 +690,7 @@ async def assess(
         if decision is not None:
             await session.refresh(decision)
         row_id = row.id
-    task = await _sync_owed_task(user_id, row_id, reason=reason, system_ids=system_ids)
+    task = await _sync_owed_task(user_id, row_id, reason=reason)
     rows = await list_adoptions(user_id, project_id=project_id, idea_id=idea_id)
     return {
         "changed": changed,
diff --git a/tests/test_family_adoption.py b/tests/test_family_adoption.py
index 63a59636..585872ef 100644
--- a/tests/test_family_adoption.py
+++ b/tests/test_family_adoption.py
@@ -62,7 +62,7 @@ GOOD = {
 
 @pytest.mark.parametrize("ground", CONFLICT_KEYS)
 def test_each_ground_holds_when_its_needs_are_met(ground):
-    kw = dict(evidence=None, conditions=None, **{**GOOD[ground]})
+    kw = {"evidence": None, "conditions": None, **GOOD[ground]}
     assert conflict_problems(ground=ground, grounds_checked=_checked(ground),
                              fold="their reasoning", **kw) == []