Product plugins that add model-visible request context without defining a tool. `workspace-context` is included by the default `dsh-agent-spine-demo` bundle and can be disabled through bundle config; `time-context`, `tmux-context`, and `session-reference` are opt-in.
The [`workspace-context` decision record](../../.agents/notes/implemented/feature/2026-06-24-workspace-context.md) explains its per-agent/session isolation and lifecycle split.