Add memory: import validation best practice

.claude/memory/MEMORY.md

@@ -31,3 +31,6 @@
 ### MCP Service
 - **[MCP Service Design](./mcp-service-design.md)** - MCP (Model Context Protocol) service architecture using FastMCP with SSE transport, JWT auth, 29 tools across 5 domains
 - **[MCP Tool Description Location](./mcp-tool-description-guide.md)** - Where to define MCP tool descriptions: in `@mcp.tool()` functions in `__init__.py`, not in `*_TOOLS` arrays
+
+### Python Code Verification
+- **[Import Validation](./python-import-validation.md)** - Use actual module imports (`python -c "from ... import ..."`) instead of `py_compile` to catch missing imports

.claude/memory/python-import-validation.md

@@ -0,0 +1,30 @@
+# Python Import Validation
+
+## Background
+
+When checking if modified Python code is correct, `py_compile` only validates syntax (e.g., balanced parentheses, valid keywords). It does **not** catch missing imports or other runtime errors (e.g., using `UUID()` without importing `UUID`).
+
+## Decision/Implementation
+
+Use actual module imports to verify code correctness:
+
+```bash
+# ✅ This catches missing imports and runtime errors
+venv/bin/python -c "
+from gns3server.api.routes.controller.dependencies.authentication import get_user_from_token
+from gns3server.api.routes.mcp.__init__ import _resolve_token
+print('All imports OK')
+"
+
+# ❌ This only checks syntax, not references
+venv/bin/python -c "import py_compile; py_compile.compile('file.py', doraise=True)"
+```
+
+## Related Files
+
+`gns3server/api/routes/controller/dependencies/authentication.py` — missed `from uuid import UUID`
+`gns3server/api/routes/mcp/__init__.py` — missed `from uuid import UUID`
+
+## Why
+
+A `NameError` at runtime is far more expensive than a failed import check. Real import testing catches the full dependency chain.