Subagent Write Verification A subagent's report that it ran and the tool returned without error is not proof the file landed on disk. Several recurring failure modes — silent Write phantoms, sandbox write blocks, isolation worktree drift, working-directory mismatch — produce a clean-looking success summary while the claimed path is empty or absent. This skill is the verification gate the main session must run before believing, committing, or chaining off any claimed write. When to Use - A dispatched agent (Claude subagent, Codex helper, Hermes worker) reports a successful / / file-creation ca…