core/agent: token-ify generic tool-result cap and compact shrinks

tests/test_agent/test_budget.py

@@ -11,21 +11,17 @@ def test_truncate_tool_result_short() -> None:
 def test_truncate_tool_result_long() -> None:
     text = "a" * 50
     out = truncate_tool_result(text, 20)
-    assert out.startswith("a" * 20)
     assert "Truncated" in out
     assert "20" in out
     assert "30" in out
-    # Generic tool results carry no resumable source → no token, no get_truncated.
-    assert "get_truncated" not in out
-    assert "TRUNCATE_TOKEN" not in out
+    # Generic tool results now embed a memory token too (resumable via get_truncated).
+    assert "truncate_token=" in out
+    assert out.startswith(("a" * 10, "a" * 20))  # marker is budgeted
 
 
-def test_truncate_tool_result_no_hint() -> None:
-    text = "a" * 50
-    out = truncate_tool_result(text, 20, hint=False)
-    assert out.startswith("a" * 20)
-    assert "truncated" in out
-    assert "get_truncated" not in out
+def test_truncate_tool_result_fits_no_marker() -> None:
+    assert truncate_tool_result("tiny", 100) == "tiny"
+    assert "Truncated" not in truncate_tool_result("tiny", 100)
 
 
 def test_estimate_message_chars() -> None: