diff --git a/src/agents/atlas/default.ts b/src/agents/atlas/default.ts
index 9ba077975..405529a40 100644
--- a/src/agents/atlas/default.ts
+++ b/src/agents/atlas/default.ts
@@ -311,7 +311,8 @@ task(category="quick", load_skills=[], run_in_background=false, prompt="Task 4..
 
 **Background management**:
 - Collect results: \`background_output(task_id="...")\`
-- Before final answer: \`background_cancel(all=true)\`
+- Before final answer, cancel DISPOSABLE tasks individually: \`background_cancel(taskId="bg_explore_xxx")\`, \`background_cancel(taskId="bg_librarian_xxx")\`
+- **NEVER use \`background_cancel(all=true)\`** — it kills tasks whose results you haven't collected yet
 </parallel_execution>
 
 <notepad_protocol>
diff --git a/src/agents/atlas/gpt.ts b/src/agents/atlas/gpt.ts
index 99bddeaa8..90d922d25 100644
--- a/src/agents/atlas/gpt.ts
+++ b/src/agents/atlas/gpt.ts
@@ -298,7 +298,8 @@ task(category="quick", load_skills=[], run_in_background=false, prompt="Task 3..
 
 **Background management**:
 - Collect: \`background_output(task_id="...")\`
-- Cleanup: \`background_cancel(all=true)\`
+- Before final answer, cancel DISPOSABLE tasks individually: \`background_cancel(taskId="bg_explore_xxx")\`, \`background_cancel(taskId="bg_librarian_xxx")\`
+- **NEVER use \`background_cancel(all=true)\`** — it kills tasks whose results you haven't collected yet
 </parallel_execution>
 
 <notepad_protocol>
diff --git a/src/agents/hephaestus.ts b/src/agents/hephaestus.ts
index 9602378fd..feac23219 100644
--- a/src/agents/hephaestus.ts
+++ b/src/agents/hephaestus.ts
@@ -292,7 +292,8 @@ Prompt structure for each agent:
 - NEVER use \`run_in_background=false\` for explore/librarian
 - Continue your work immediately after launching background agents
 - Collect results with \`background_output(task_id="...")\` when needed
-- BEFORE final answer: \`background_cancel(all=true)\` to clean up
+- BEFORE final answer, cancel DISPOSABLE tasks individually: \`background_cancel(taskId="bg_explore_xxx")\`, \`background_cancel(taskId="bg_librarian_xxx")\`
+- **NEVER use \`background_cancel(all=true)\`** — it kills tasks whose results you haven't collected yet
 
 ### Search Stop Conditions
 
diff --git a/src/agents/sisyphus.ts b/src/agents/sisyphus.ts
index 9ac7be1bc..1079099be 100644
--- a/src/agents/sisyphus.ts
+++ b/src/agents/sisyphus.ts
@@ -306,9 +306,9 @@ result = task(..., run_in_background=false)  // Never wait synchronously for exp
 ### Background Result Collection:
 1. Launch parallel agents → receive task_ids
 2. Continue immediate work
-3. When results needed: \`background_output(task_id=\"...\")\`
-4. Before final answer, cancel DISPOSABLE tasks (explore, librarian) individually: \`background_cancel(taskId=\"bg_explore_xxx\")\`, \`background_cancel(taskId=\"bg_librarian_xxx\")\`
-5. **NEVER cancel Oracle.** ALWAYS collect Oracle result via \`background_output(task_id=\"bg_oracle_xxx\")\` before answering — even if you already have enough context.
+3. When results needed: \`background_output(task_id="...")\`
+4. Before final answer, cancel DISPOSABLE tasks (explore, librarian) individually: \`background_cancel(taskId="bg_explore_xxx")\`, \`background_cancel(taskId="bg_librarian_xxx")\`
+5. **NEVER cancel Oracle.** ALWAYS collect Oracle result via \`background_output(task_id="bg_oracle_xxx")\` before answering — even if you already have enough context.
 6. **NEVER use \`background_cancel(all=true)\`** — it kills Oracle. Cancel each disposable task by its specific taskId.
 
 ### Search Stop Conditions
@@ -444,7 +444,7 @@ If verification fails:
 3. Report: "Done. Note: found N pre-existing lint errors unrelated to my changes."
 
 ### Before Delivering Final Answer:
-- Cancel DISPOSABLE background tasks (explore, librarian) individually via \`background_cancel(taskId=\"...\")\`
+- Cancel DISPOSABLE background tasks (explore, librarian) individually via \`background_cancel(taskId="...")\`
 - **NEVER use \`background_cancel(all=true)\`.** Always cancel individually by taskId.
 - **Always wait for Oracle**: When Oracle is running and you have gathered enough context from your own exploration, your next action is \`background_output\` on Oracle — NOT delivering a final answer. Oracle's value is highest when you think you don't need it.
 </Behavior_Instructions>