docs(asset-gen): import_model_file self-contained-format caveat + skill tool-name fix

Claude-Session: https://claude.ai/code/session_01NoHk4f7N1vUFs7gu817ihm

Author: Scriptwonder

.claude/skills/blender-to-unity/SKILL.md

@@ -12,7 +12,7 @@ directly.
 ## Preconditions
 - Both `mcp__blender__*` tools and MCP for Unity tools are connected.
 - A model exists in the Blender scene (confirm with `mcp__blender__get_scene_info` /
-  `get_object_info`). If empty, stop and tell the user — this skill does not generate models.
+  `mcp__blender__get_object_info`). If empty, stop and tell the user — this skill does not generate models.
 
 ## Steps
 1. **Resolve the Unity project path.** Read `mcpforunity://editor/state` for the project
@@ -43,3 +43,4 @@ directly.
   "GLB import requires glTFast", re-export as FBX (or install glTFast from the Dependencies tab).
 - Keep one model per handoff; for batches, repeat the loop with distinct names.
 - This skill never sends API keys or file bytes over the MCP bridge — Unity reads the file from disk.
+- `import_model_file` copies only the single source file; for multi-file exports (a text `.gltf` with an external `.bin`, or an `.obj` with a sibling `.mtl`/textures), zip them first and pass the `.zip` — a bare `.gltf`/`.obj` will lose its sidecars.

Server/src/services/tools/import_model_file.py

@@ -24,7 +24,9 @@
         "under Assets/ and run through Unity's model-import pipeline (scale-normalize, material "
         "settings; glTF requires glTFast). Carries no API keys and no file bytes over the bridge.\n\n"
         "Params: source_path (absolute or Assets-relative path to a .fbx/.obj/.glb/.gltf/.zip), "
-        "name, output_folder (under Assets/), target_size. Returns { asset_path, asset_guid }."
+        "name, output_folder (under Assets/), target_size. Returns { asset_path, asset_guid }.\n\n"
+        "For multi-file exports (a text .gltf with an external .bin, or an .obj with a sibling "
+        ".mtl/textures), zip them and pass the .zip — a bare .gltf/.obj is copied without its sidecars."
     ),
     annotations=ToolAnnotations(
         title="Import Model File",