# Limits and troubleshooting [Back to AI agents & app data](https://rustic-game-engine.pages.dev/markdown/guides/ai-agents.md). - These tools operate locally for the current OS user. App-data instructions are not included when sharing or checking in a game directory. Moving the project changes its storage key; copy important instructions through the tools if needed. - Reads and writes accept UTF-8 text up to 2 MiB. Paths are relative to the selected agent directory and use `/` separators. Absolute paths (including Windows drive paths on Linux), backslashes, colons, `..`, `.git`, and symlinks that escape it are rejected. For example, use `notes/behavior.md`, not `C:/notes/behavior.md` or `notes\behavior.md`. Project and shared user scopes do not expose other projects' storage. A path error means you should call `list_agent_files`, then use a relative path within the selected scope. - If the tools are missing, reopen the editor and reload your agent's MCP server. Confirm the installed backend executable exists. You can rerun `rustic-agent-backend.exe --install-user-integrations` to register it again. - “No Rustic project is selected” is a tool error, not a failed MCP startup. Call `workspace_info` with `{"project_root":"C:/Games/MyGame"}` using an absolute path to a readable game directory containing `project.engine`. Later file and scene tools use that selected game. An invalid selection reports a tool error and keeps the previous selection; it does not close the server. You can also set `--project` in the MCP registration and reload it. - An older backend may exit with “The supplied folder is not a readable Rustic project” before connecting when Codex starts outside a game. Point that registration at the game with `--project`, or install the updated backend and reload the connection. Opening the editor alone does not replace an already running MCP process. - If a file is missing, call `list_agent_files` and check the scope and relative path. Ordinary `read_file` and `write_file` address game content; agent metadata uses `read_agent_file` and `write_agent_file`. - If migration or saving fails, check permissions on the project and Rustic app data and the editor's startup error output. Existing files are only removed after their contents have been stored; unrelated agent directories stay intact.