diff --git a/experiments/2026-05-12-cross-model-authoring/format-findings.md b/experiments/2026-05-12-cross-model-authoring/format-findings.md
index d6e6c73..44cbaee 100644
--- a/experiments/2026-05-12-cross-model-authoring/format-findings.md
+++ b/experiments/2026-05-12-cross-model-authoring/format-findings.md
@@ -127,6 +127,17 @@ So the "modern" structured-output channel is the worst surface here, for
 exactly the reason the rule predicts: AST JSON is maximal extra bookkeeping
 with no redundant cue.
 
+**Re-run with max_tokens raised 2500 → 8000** (the bad-json cases at 2500 were
+truncation, so this is the fair correction): it did NOT help — 1/8, slightly
+worse. The full budget just gives the model more room to degenerate. At L2
+("print 7", a trivial program) Qwen emitted **8000 tokens — ~20 KB of AST JSON
+— and ran off the end** (a repetition loop on a one-line program); at L7 it
+produced JSON nested so deep the parser hit its recursion limit. So the AST-JSON
+surface is not budget-limited in a recoverable way: given more room it loops or
+nests without end. The verbose surface invites the same degeneration the
+annotated-paren run hit at its hardest level — but here it strikes even the
+trivial tasks.
+
 ## Overall finding across all six surfaces
 
 | surface | green | structure marking |
diff --git a/experiments/2026-05-12-cross-model-authoring/qwen-tool-8k.md b/experiments/2026-05-12-cross-model-authoring/qwen-tool-8k.md
new file mode 100644
index 0000000..9638adb
--- /dev/null
+++ b/experiments/2026-05-12-cross-model-authoring/qwen-tool-8k.md
@@ -0,0 +1,631 @@
+# Qwen format probe — tool-calling / structured AST
+
+**Model:** Qwen/Qwen3-Coder-Next; submit_program tool, forced; AST written directly to .ail.json.
+
+---
+
+## L0_const — ✅ green
+
+tokens: prompt=1078 completion=162
+
+submitted AST:
+```json
+{
+ "schema": "ailang/v0",
+ "name": "m",
+ "imports": [],
+ "defs": [
+  {
+   "kind": "fn",
+   "name": "answer",
+   "params": [],
+   "type": {
+    "k": "fn",
+    "param_modes": [],
+    "params": [],
+    "ret": {
+     "k": "con",
+     "name": "Int",
+     "effects": []
+    },
+    "ret_mode": "own",
+    "effects": []
+   },
+   "body": {
+    "lit": {
+     "kind": "int",
+     "value": 42
+    },
+    "t": "lit"
+   }
+  }
+ ]
+}
+```
+
+
+## L1_arith — ❌ check
+
+tokens: prompt=1079 completion=170
+
+submitted AST:
+```json
+{
+ "schema": "ailang/v0",
+ "name": "m",
+ "imports": [],
+ "defs": [
+  {
+   "kind": "fn",
+   "name": "triple",
+   "params": [
+    "x"
+   ],
+   "type": {
+    "k": "fn",
+    "param_modes": [
+     "own"
+    ],
+    "params": [
+     {
+      "k": "con",
+      "name": "Int"
+     }
+    ],
+    "ret": {
+     "k": "con",
+     "name": "Int"
+    },
+    "ret_mode": "own",
+    "effects": []
+   },
+   "body": {
+    "t": "app",
+    "fn": {
+     "t": "var",
+     "name": "*"
+    },
+    "args": [
+     {
+      "t": "var",
+      "name": "x"
+     },
+     {
+      "t": "var",
+      "name": "x"
+     },
+     {
+      "t": "var",
+      "name": "x"
+     }
+    ]
+   }
+  }
+ ]
+}
+```
+
+**check:**
+```
+error: [arity-mismatch] triple: arity mismatch for `*`: expected 2 args, got 3
+```
+
+## L2_print — ❌ bad-json
+
+tokens: prompt=1075 completion=8000
+
+submitted AST:
+```json
+{"module": {"schema": "ailang/v0", "name": "m", "imports": [], "defs": [{"kind": "fn", "name": "main", "params": [], "type": {"k": "fn", "param_modes": [], "params": [], "ret": {"k": "con", "name": "Unit"}, "effects": ["IO"]}, "body": {"t": "seq", "lhs": {"t": "app", "fn": {"t": "var", "name": "print"}, "args": [{"t": "app", "fn": {"t": "var", "name": "print"}, "args": [{"t": "var", "name": "x"}]}
+```
+
+**bad-json:**
+```
+tool arguments not valid JSON: Unterminated string starting at: line 1 column 20034 (char 20033)
+```
+
+## L3_adt — ❌ check
+
+tokens: prompt=1092 completion=253
+
+submitted AST:
+```json
+{
+ "schema": "ailang/v0",
+ "name": "m",
+ "imports": [],
+ "defs": [
+  {
+   "kind": "type",
+   "name": "Light",
+   "ctors": [
+    {
+     "name": "Red",
+     "fields": []
+    },
+    {
+     "name": "Green",
+     "fields": []
+    }
+   ]
+  },
+  {
+   "kind": "fn",
+   "name": "code",
+   "params": [
+    "light"
+   ],
+   "type": {
+    "k": "fn",
+    "param_modes": [
+     "own"
+    ],
+    "params": [
+     {
+      "k": "con",
+      "name": "Light"
+     }
+    ],
+    "ret": {
+     "k": "con",
+     "name": "Int"
+    },
+    "ret_mode": "own",
+    "effects": []
+   },
+   "body": {
+    "kind": "match",
+    "scrutinee": {
+     "name": "light",
+     "t": "var"
+    },
+    "arms": [
+     {
+      "pat": {
+       "p": "ctor",
+       "ctor": "Red"
+      },
+      "body": {
+       "lit": {
+        "kind": "int",
+        "value": 0
+       },
+       "t": "lit"
+      }
+     },
+     {
+      "pat": {
+       "p": "ctor",
+       "ctor": "Green"
+      },
+      "body": {
+       "lit": {
+        "kind": "int",
+        "value": 1
+       },
+       "t": "lit"
+      }
+     }
+    ]
+   }
+  }
+ ]
+}
+```
+
+**check:**
+```
+Error: schema/parse error in /tmp/abl/m.ail.json: json: missing field `t` at line 80 column 3
+
+Caused by:
+    0: json: missing field `t` at line 80 column 3
+    1: missing field `t` at line 80 column 3
+```
+
+## L4_rec — ❌ check
+
+tokens: prompt=1104 completion=1031
+
+submitted AST:
+```json
+{
+ "schema": "ailang/v0",
+ "name": "m",
+ "imports": [],
+ "defs": [
+  {
+   "kind": "type",
+   "name": "IntList",
+   "ctors": [
+    {
+     "name": "Nil",
+     "fields": []
+    },
+    {
+     "name": "Cons",
+     "fields": [
+      {
+       "k": "con",
+       "name": "Int"
+      },
+      {
+       "k": "con",
+       "name": "IntList"
+      }
+     ]
+    }
+   ]
+  },
+  {
+   "kind": "fn",
+   "name": "length",
+   "params": [
+    "xs"
+   ],
+   "type": {
+    "k": "fn",
+    "param_modes": [
+     "own"
+    ],
+    "params": [
+     {
+      "k": "con",
+      "name": "IntList"
+     }
+    ],
+    "ret": {
+     "k": "con",
+     "name": "Int"
+    },
+    "ret_mode": "own",
+    "effects": []
+   },
+   "body": {
+    "t": "match",
+    "scrutinee": {
+     "t": "var",
+     "name": "xs"
+    },
+    "arms": [
+     {
+      "t": "arm",
+      "pat": {
+       "p": "ctor",
+       "ctor": "Nil",
+       "fields": []
+      },
+      "body": {
+       "t": "lit",
+       "lit": {
+        "kind": "int",
+        "value": 0
+       }
+      },
+      "arms": [
+       {
+        "t": "arm",
+        "pat": {
+         "p": "ctor",
+         "ctor": "Cons",
+         "fields": [
+          {
+           "p": "var",
+           "name": "h"
+          },
+          {
+           "p": "var",
+           "name": "t"
+          }
+         ]
+        },
+        "body": {
+         "t": "app",
+         "fn": {
+          "t": "var",
+          "name": "
+```
+
+**check:**
+```
+Error: schema/parse error in /tmp/abl/m.ail.json: json: missing field `lit` at line 227 column 3
+
+Caused by:
+    0: json: missing field `lit` at line 227 column 3
+    1: missing field `lit` at line 227 column 3
+```
+
+## L5_series_len — ❌ check
+
+tokens: prompt=1494 completion=651
+
+submitted AST:
+```json
+{
+ "schema": "ailang/v0",
+ "name": "m",
+ "imports": [],
+ "defs": [
+  {
+   "kind": "fn",
+   "name": "s",
+   "params": [],
+   "type": {
+    "k": "fn",
+    "param_modes": [],
+    "params": [],
+    "ret": {
+     "k": "con",
+     "name": "Unit"
+    },
+    "ret_mode": "own",
+    "effects": [
+     "IO"
+    ]
+   },
+   "body": {
+    "body": {
+     "body": {
+      "body": {
+       "lhs": {
+        "args": [
+         {
+          "name": "s3",
+          "t": "var"
+         }
+        ],
+        "fn": {
+         "name": "Series.len",
+         "t": "var"
+        },
+        "t": "app"
+       },
+       "fn": {
+        "name": "print",
+        "t": "var"
+       },
+       "t": "app"
+      },
+      "rhs": {
+       "args": [
+        {
+         "kind": "str",
+         "value": "\n",
+         "t": "lit"
+        }
+       ],
+       "op": "io/print_str",
+       "t": "do"
+      },
+      "t": "seq"
+     },
+     "name": "s3",
+     "t": "let",
+     "value": {
+      "args": [
+       {
+        "name": "s2",
+        "t": "var"
+       },
+       {
+        "kind": "float",
+        "bits": "400000000000000",
+        "t": "lit"
+       }
+      ],
+      "fn": {
+       "name": "Series.push",
+       "t": "var"
+      },
+      "t": "app"
+     }
+    },
+    "name": "s2",
+    "t": "let",
+    "value": {
+     "args": [
+      {
+       "name": "s",
+       "t": "var"
+      },
+      {
+       "kind": "float",
+       "bits": "3ff00
+```
+
+**check:**
+```
+Error: schema/parse error in /tmp/abl/m.ail.json: json: missing field `lit` at line 124 column 3
+
+Caused by:
+    0: json: missing field `lit` at line 124 column 3
+    1: missing field `lit` at line 124 column 3
+```
+
+## L6_series_at — ❌ check
+
+tokens: prompt=1502 completion=740
+
+submitted AST:
+```json
+{
+ "schema": "ailang/v0",
+ "name": "m",
+ "imports": [],
+ "defs": [
+  {
+   "kind": "fn",
+   "name": "main",
+   "params": [],
+   "type": {
+    "k": "fn",
+    "param_modes": [],
+    "params": [],
+    "ret": {
+     "k": "con",
+     "name": "Unit"
+    },
+    "ret_mode": "own",
+    "effects": [
+     "IO"
+    ]
+   },
+   "body": {
+    "body": {
+     "body": {
+      "body": {
+       "lhs": {
+        "args": [
+         {
+          "args": [
+           {
+            "name": "s3",
+            "t": "var"
+           },
+           {
+            "kind": "value",
+            "value": {
+             "lit": {
+              "kind": "int",
+              "value": 0
+             },
+             "t": "lit"
+            }
+           }
+          ],
+          "fn": {
+           "name": "Series.at",
+           "t": "var"
+          },
+          "t": "app"
+         }
+        ],
+        "fn": {
+         "name": "print",
+         "t": "var"
+        },
+        "t": "app"
+       },
+       "rhs": {
+        "args": [
+         {
+          "lit": {
+           "kind": "str",
+           "value": "\n"
+          },
+          "t": "lit"
+         },
+         {
+          "op": "io/print_str",
+          "t": "do"
+         }
+        ],
+        "t": "seq"
+       },
+       "name": "s3",
+       "t": "let",
+       "value": {
+        "args": [
+         {
+          "name": "s2",
+          "t": "var"
+         },
+         {
+        
+```
+
+**check:**
+```
+Error: schema/parse error in /tmp/abl/m.ail.json: json: missing field `t` at line 149 column 3
+
+Caused by:
+    0: json: missing field `t` at line 149 column 3
+    1: missing field `t` at line 149 column 3
+```
+
+## L7_sma — ❌ check
+
+tokens: prompt=1588 completion=4382
+
+submitted AST:
+```json
+{
+ "schema": "ailang/v0",
+ "name": "m",
+ "imports": [],
+ "defs": [
+  {
+   "kind": "fn",
+   "name": "main",
+   "params": [],
+   "type": {
+    "k": "fn",
+    "param_modes": [],
+    "params": [],
+    "ret": {
+     "k": "con",
+     "name": "Unit"
+    },
+    "ret_mode": "own",
+    "effects": [
+     "IO"
+    ]
+   },
+   "body": {
+    "body": {
+     "body": {
+      "body": {
+       "body": {
+        "body": {
+         "body": {
+          "body": {
+           "body": {
+            "body": {
+             "body": {
+              "body": {
+               "body": {
+                "body": {
+                 "body": {
+                  "body": {
+                   "body": {
+                    "body": {
+                     "body": {
+                      "body": {
+                       "body": {
+                        "body": {
+                         "body": {
+                          "body": {
+                           "body": {
+                            "body": {
+                             "body": {
+                              "body": {
+                               "body": {
+                                "body": {
+                                 "body": {
+                                  "body": {
+                                   "body": {
+                                    "body": {
+                                     "body": {
+                                      
+```
+
+**check:**
+```
+Error: schema/parse error in /tmp/abl/m.ail.json: json: recursion limit exceeded at line 147 column 263
+
+Caused by:
+    0: json: recursion limit exceeded at line 147 column 263
+    1: recursion limit exceeded at line 147 column 263
+```
+
+
+---
+## Ladder
+
+- L0_const: ✅ green
+- L1_arith: ❌ check
+- L2_print: ❌ bad-json
+- L3_adt: ❌ check
+- L4_rec: ❌ check
+- L5_series_len: ❌ check
+- L6_series_at: ❌ check
+- L7_sma: ❌ check
\ No newline at end of file
diff --git a/experiments/2026-05-12-cross-model-authoring/qwen_tool.py b/experiments/2026-05-12-cross-model-authoring/qwen_tool.py
index 7639d16..3869b03 100644
--- a/experiments/2026-05-12-cross-model-authoring/qwen_tool.py
+++ b/experiments/2026-05-12-cross-model-authoring/qwen_tool.py
@@ -16,7 +16,7 @@ ENDPOINT="https://openai.inference.de-txl.ionos.com/v1/chat/completions"
 MODEL="Qwen/Qwen3-Coder-Next"
 REPO=Path(__file__).resolve().parents[2]
 AIL=os.environ.get("AIL_BIN", str(REPO/"target/debug/ail"))
-DOC=REPO/"experiments/2026-05-12-cross-model-authoring/qwen-tool.md"
+DOC=REPO/"experiments/2026-05-12-cross-model-authoring/qwen-tool-8k.md"
 
 def ail_ast(src):
     p=Path("/tmp/abl/_fs.ail"); p.write_text(src+"\n")
@@ -84,7 +84,7 @@ STAGES=[
 ]
 
 def call(system,task):
-    body=json.dumps({"model":MODEL,"temperature":0.2,"max_tokens":2500,
+    body=json.dumps({"model":MODEL,"temperature":0.2,"max_tokens":8000,
         "messages":[{"role":"system","content":system},{"role":"user","content":task}],
         "tools":[TOOL],"tool_choice":{"type":"function","function":{"name":"submit_program"}}}).encode()
     req=urllib.request.Request(ENDPOINT,data=body,headers={