diff --git a/model_specs/firered_audio.json b/model_specs/firered_audio.json
index 7e54daf4b..32f05f856 100644
--- a/model_specs/firered_audio.json
+++ b/model_specs/firered_audio.json
@@ -182,14 +182,6 @@
         "min": 1,
         "default": 1024
       },
-      {
-        "name": "helper_graph_arena_mb",
-        "type": "int",
-        "description": "Helper graph arena size in MiB; default 256.",
-        "required": false,
-        "min": 1,
-        "default": 256
-      },
       {
         "name": "weight_context_mb",
         "type": "int",
diff --git a/model_specs/granite5asr.json b/model_specs/granite5asr.json
index f576999fb..ae85c315d 100644
--- a/model_specs/granite5asr.json
+++ b/model_specs/granite5asr.json
@@ -22,13 +22,6 @@
   },
   "options": {
     "request": [
-      {
-        "name": "language",
-        "type": "string",
-        "description": "Recognition language (currently English).",
-        "required": false,
-        "default": "en"
-      },
       {
         "name": "audio_chunk_mode",
         "type": "enum",
diff --git a/model_specs/heartmula.json b/model_specs/heartmula.json
index 0392f868e..d6f87fdec 100644
--- a/model_specs/heartmula.json
+++ b/model_specs/heartmula.json
@@ -26,13 +26,13 @@
         "name": "lyrics",
         "type": "string",
         "description": "Lyrics text.",
-        "required": false
+        "required": true
       },
       {
         "name": "tags",
         "type": "string",
         "description": "Comma-separated music tags.",
-        "required": false
+        "required": true
       },
       {
         "name": "duration_sec",
diff --git a/model_specs/irodori_tts.json b/model_specs/irodori_tts.json
index 4da584fe6..ccebb6390 100644
--- a/model_specs/irodori_tts.json
+++ b/model_specs/irodori_tts.json
@@ -74,6 +74,8 @@
         "type": "enum",
         "description": "Text chunking mode; default endline.",
         "values": [
+          "default",
+          "tag_aware",
           "japanese",
           "endline"
         ],
diff --git a/model_specs/midashenglm_gen.json b/model_specs/midashenglm_gen.json
index 5704bf86f..0f92dbec0 100644
--- a/model_specs/midashenglm_gen.json
+++ b/model_specs/midashenglm_gen.json
@@ -67,9 +67,9 @@
       {
         "name": "seed",
         "type": "int",
-        "description": "Generation seed; -1 selects a random seed.",
+        "description": "Generation seed; parsed as an unsigned 32-bit value, so negative seeds are rejected.",
         "required": false,
-        "min": -1,
+        "min": 0,
         "max": 2147483647,
         "default": 0
       }