shell-discipline— agent skill

Shell Commands

• One command per call — keep commands small, readable, and atomic. Don't chain with &&, ;, or cd dir && command. Use separate calls — first cd, then the command.
• No inline env vars — don't use VAR=value command. Set env separately or use proper auth tools.

Git Auth

• Use gh auth login / gh auth switch to switch GitHub accounts — never prefix with GH_TOKEN=....

Why

Each chained command is one opaque action to the permission layer; splitting them gives one auditable tool call per intent. Inline env vars hide configuration in the command line and leak secrets into shell history; explicit auth tools (gh auth login) keep credentials in the keyring where they belong.

Prerequisites

• A POSIX shell (bash or zsh).
• For the Git Auth rule: gh CLI installed and authenticated.

Failure modes

• `gh auth login` fails or token expired. Re-run gh auth login -h github.com interactively, then gh auth status to verify. Don't paste the token into a shell command.
• Account switch needed. gh auth switch -u <user>. If that user's token is invalid, re-auth that account before switching.
• Command needs elevated privileges. Set up the privilege out-of-band (sudoers entry, group membership) rather than prefixing the command with sudo inline; an unattended agent shouldn't be entering passwords.
• Shell aliases that hide what runs. Avoid invoking aliases in agent procedures; spell out the real command so it's auditable.