Function hook_command 

pub fn hook_command(
    head: &str,
    mode: Mode,
    log_dir: Option<&str>,
    no_log: bool,
    nudge_pipelines: bool,
) -> String

The PreToolUse hook command written into settings, built on head — the invocation prefix, "ct steer hook" by default or a pinned "<abs-path> hook" (see --pin). Tool-call logging is on by default (to .ct/tclog/), so the bare command already logs; no_log/log_dir bake in the logging override, and nudge_pipelines bakes in --nudge-pipelines.