# Shared Rule — Large Prompts via `prompt_file`

> **Canonical source of truth.** This file is the single authoritative copy of
> the large-prompts-via-prompt_file rule. The following skills reference this
> rule via an `<!-- inject -->` comment and MUST NOT maintain their own copies:
>
> - `review-code/SKILL.md`
> - `implement/SKILL.md`
> - `frontend/SKILL.md`
>
> (The `roadmap`, `requirements-elicitation`, `design`, and `plan-iterations`
> referencing skills were archived 2026-08-21, [org-internal #3072] phase 3 — see
> `.octopus/archive/skills/`; their copies of this directive moved with them.)
>
> **When editing:** update this file only. Each skill references this file via a
> one-line `<!-- inject -->` directive — there are no verbatim mirrors to sync.
>
> This is a reference document, not a skill (no `SKILL.md` frontmatter), so the
> skill loader does not register it.

## Why a canonical copy exists

The `task-tool-discipline` rule in `AGENTS.md` requires large prompts to be
written to a file and passed via `prompt_file`. This guidance applies to every
skill that dispatches sub-agents with potentially large prompts. A single
canonical source prevents drift and ensures the rule, file path convention
(`/tmp/octopus/<slug>.md`), and justification stay consistent.

## Canonical text

> **Large Prompts via `prompt_file`**
>
> Follow the `task-tool-discipline` rule in `AGENTS.md`: any prompt expected to
> exceed ~1 KB MUST be written to a file first and passed via the `task` tool's
> `prompt_file` parameter (e.g. `/tmp/octopus/<slug>.md`), never inlined.