diff --git a/internal/scaffold/fullsend-repo/agents/fix.md b/internal/scaffold/fullsend-repo/agents/fix.md
index d82e6c72d..dacc5775e 100644
--- a/internal/scaffold/fullsend-repo/agents/fix.md
+++ b/internal/scaffold/fullsend-repo/agents/fix.md
@@ -72,6 +72,11 @@ triggered this fix run (e.g., `"orgname-review[bot]"` for bot-triggered,
 triggers. When triggered by a human (username doesn't end in `[bot]`), the
 `HUMAN_INSTRUCTION` environment variable contains the instruction text.
 
+**Important:** `TRIGGER_SOURCE` is a GitHub username — not the value you
+write to `fix-result.json`. The `trigger_source` field in structured output
+must be normalized to `"bot"` or `"human"` (the schema enum). Map it:
+if the username ends in `[bot]`, use `"bot"`; otherwise use `"human"`.
+
 ## Zero-trust principle
 
 You do not trust the review agent's analysis unconditionally. The review
diff --git a/internal/scaffold/fullsend-repo/skills/fix-review/SKILL.md b/internal/scaffold/fullsend-repo/skills/fix-review/SKILL.md
index cee7b42d4..7183c6700 100644
--- a/internal/scaffold/fullsend-repo/skills/fix-review/SKILL.md
+++ b/internal/scaffold/fullsend-repo/skills/fix-review/SKILL.md
@@ -95,8 +95,14 @@ echo "FIX_ITERATION=${FIX_ITERATION:-1}"
 ```
 
 - `PR_NUMBER` — which PR to fix (required)
-- `TRIGGER_SOURCE` — GitHub username that triggered the fix (e.g., `"orgname-review[bot]"` or `"alice"`)
-- `HUMAN_INSTRUCTION` — the human's instruction text (only when `TRIGGER_SOURCE` doesn't end in `[bot]`)
+- `TRIGGER_SOURCE` — GitHub username that triggered the fix (e.g.,
+  `"orgname-review[bot]"` or `"alice"`). **This is a username, not the
+  value you write to `fix-result.json`.** Derive the normalized trigger
+  type now — you will need it in step 9:
+  - If `TRIGGER_SOURCE` ends in `[bot]` → trigger type is `"bot"`
+  - Otherwise → trigger type is `"human"`
+- `HUMAN_INSTRUCTION` — the human's instruction text (only when
+  `TRIGGER_SOURCE` doesn't end in `[bot]`)
 - `FIX_ITERATION` — which iteration of the review→fix loop this is
 
 If `PR_NUMBER` is not set, stop.
@@ -401,16 +407,29 @@ Write a JSON file to `$FULLSEND_OUTPUT_DIR/fix-result.json`:
 }
 ```
 
+**Schema compliance — read carefully.** The schema uses
+`additionalProperties: false` at both the top level and inside each action
+object. Any extra fields you invent will cause validation to fail. Only use
+the fields shown in this section.
+
+**`trigger_source` field:** This must be the **normalized trigger type** you
+derived in step 1 — either `"bot"` or `"human"`. Do NOT use the raw
+`TRIGGER_SOURCE` environment variable value (the GitHub username). The schema
+enforces an enum of `["bot", "human"]`; any other value fails validation.
+
 **Action types:**
 
-- `fix` — You fixed the code per the reviewer's feedback. The post-script
+- `fix` — You fixed the code per the reviewer's feedback. **Required fields
+  for fix actions:** `type`, `finding`, `description`. The post-script
   includes this in the summary comment.
-- `disagree` — You determined the feedback is incorrect or out of scope. The
-  post-script includes your reason in the summary. The reviewer can insist
-  in the next review cycle.
-
-**Required fields:** `pr_number`, `trigger_source`, `actions`, `summary`,
-`tests_passed`, `files_changed`.
+- `disagree` — You determined the feedback is incorrect or out of scope.
+  **Required fields for disagree actions:** `type`, `finding`, `reason`.
+  The post-script includes your reason in the summary. The reviewer can
+  insist in the next review cycle.
+
+**Required top-level fields:** `pr_number`, `trigger_source`, `actions`,
+`summary`, `tests_passed`, `files_changed`. The `actions` array must
+contain at least one item.
 
 Write the file using `Bash`: