Read-only snapshot of the host hardware and OS: battery level, storage usage, CPU architecture and memory. Use it when the answer depends on the physical device: free space before a download, battery before a long job, arch before picking a binary. Not for process or server state: use server_health for pid/uptime/counters of this MCP server, resolve_path to validate one path, and path_adapter for the runtime's path environment. Never raises: a field that cannot be read is reported with source unavailable. Returns {battery, storage, arch, memory}.

Read-only self-diagnostics for this MCP server process: pid/ppid, runtime class, uptime, request and tool-call counters, tracked live child processes, RSS, and the Android Phantom Process Killer risk assessment. Use it to verify the server is alive, to debug client-side disconnects, or to check whether orphaned children are accumulating on Android. Not for the device itself: use device_status for battery, storage, arch and memory. Returns {server, children, memory, phantom_process}.

Resolve and validate one filesystem path in the runtime this server runs in: expands ~/$HOME/$PREFIX/$TMPDIR, follows symlinks, reports the mount backing the path, and lists every Android-equivalent spelling (/sdcard <-> /storage/emulated/0 <-> $HOME/storage/shared). Equivalent inputs: /sdcard/Download/x.txt, $HOME/storage/shared/Download/x.txt, ~/storage/shared/Download/x.txt, and relative docs/report.md (against cwd). Expansion: ~ and $HOME become the server's HOME; $PREFIX is the install prefix (e.g. /data/data/com.termux/files/usr); $TMPDIR is the server's own temp dir, never the client's. Useful when a path has to be handed to a shell command or another tool; not needed for paths already known-good on plain Linux. Sibling boundary: path_adapter reports the environment map itself (env class, HOME/PREFIX/TMPDIR, mount roots) and takes no arguments; resolve_path reports one concrete path. Use path_adapter for the environment, resolve_path for a candidate path. Returns {input, expanded, resolved, env, exists, is_dir, is_file, is_symlink, readable, writable, executable, mount, alternatives, warnings}.

Report the runtime's path environment so you can translate host paths correctly: detected env class (termux/proot/android/linux), HOME/PREFIX/TMPDIR, each Android shared-storage root with its real mount, all noexec mounts that block in-place script execution, and runtime-specific notes. Takes no arguments. Sibling boundary: this answers the environment question (env class, HOME/PREFIX/TMPDIR, mount roots); resolve_path answers the per-path question (expansion, mount, alternatives for one path). Use path_adapter when the environment itself is unknown, resolve_path to validate a single candidate path. Returns {env, home, prefix, tmpdir, python, platform, android_roots, noexec_mounts, notes}.