Harden MCP tool composition

README.md

@@ -138,14 +138,16 @@ Tool calling semantics:
   zeroes) and an optional `article_name_hint`.
 - `calculate_roll_diameter` uses `roll_length_m` for the material length on one
   roll. Diameter and thickness inputs are in mm; `width_m` is in m;
-  `area_weight_g_m2` is in g/m². `include_roll_weight` requests the optional
-  kilogram result.
+  `area_weight_g_m2` is in g/m². It always requests the available kilogram
+  result and, on success, returns `transport_roll_inputs`, the browser-equivalent
+  transport bundle.
 - `analyze_transport_capacity` uses roll/core diameters in mm; roll width and
   transport dimensions in m; and roll/payload weights in kg.
   `product_length_m` is the material length represented by one roll, used only
-  for reported square metres. The supplied `roll_weight_kg` is passed through
-  unchanged. Callers may use a canonical `transport_preset` or provide custom
-  transport dimensions and `max_weight_kg`.
+  for reported square metres. For a chained calculation, pass every field from
+  `transport_roll_inputs` unchanged. The supplied `roll_weight_kg` is passed
+  through unchanged. Callers may use a canonical `transport_preset` or provide
+  custom transport dimensions and `max_weight_kg`.
 
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