This skill deliberately restricts all file operations to a user-approved workspace. The agent must never write files outside the declared directory without fresh, explicit permission from the user. Because agent runtimes and UIs commonly cache filesystem state, this version of the skill **mandates** a Write → Verify step after every write. The read_files and terminal_shell tools are required for verification to ensure writes actually land and are observable. This primitive is the required low-level executor for any skill that mutates Agensi skill definitions (SKILL.md / agents/grok.yaml). It must be used together with Safe Code Changes with Grok (v1.5.0+) for library publishing and catalog sync. Git worktree awareness was added because many sessions run inside `.grok/worktrees/`. The agent must always identify the primary development tree vs any worktree checkout and get explicit user confirmation before writing. environment_variables: - "VERIFY_AFTER_WRITE — Force immediate post-write verification (read_file + terminal fallback). Default: true." - "PREFER_PRIMARY_TREE — Strongly prefer writing to the user’s canonical / primary development tree rather than a git worktree. Default: true." - "CHECK_VERSION_BEFORE_WRITE — Read frontmatter version: (or equivalent) before editing any conventionally versioned file. Default: true." - "STRICT_WRITE_VERIFICATION — Fail the operation and block continuation if post-write verification does not exactly match the approved content. Default: true."