Plan Sketch

What it does

When your agent uses it

• You want an approach and step ordering before implementation

Example prompts

• “/plan-sketch”

Requirements

• Python 3

Workflow steps

3 steps, taken from the first numbered list in SKILL.md.

1. 1A sketch markdown file (usually under sketch/, or an explicit --output path if provided).
2. 2A small, parseable Questions for user block in the subagent's stdout output so wrapper skills can ask the user without reading the sketch…
3. 3A machine-readable JSON Questions block in stdout so wrapper skills can parse choices programmatically.

What it can do on your machine

Read from SKILL.md and the folder at commit 6cad3b9. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Ships 1 file in scripts/ (Python), which the agent can run.

  Shell commands in SKILL.md call:

  • git
  • python3
  • claude

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  No URLs in SKILL.md. Its commands use git, which can reach the network depending on how they are called.

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Plan Sketch loads about 1.4k tokens when it runs, and up to ~2.3k if it reads all its reference files. Until then it costs about 51 tokens; SKILL.md has 629 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~51

When it runs · the whole SKILL.md, loaded when a task matches

~1.4k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~2.3k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); the scripts in this folder are not scanned.

SKILL.md

The full file from besimple-oss/broccoli at commit 6cad3b9, republished under its MIT licence (© besimple-oss). 629 words, ~1,401 tokens.

name

plan-sketch

description

Do bounded research (official docs first) and produce a high-level implementation sketch in `sketch/<generated-name>.md`. Use when you want an approach and step ordering before implementation.

resolve_skill_dir() {
  local name="$1"
  local repo_root=""
  repo_root="$(git rev-parse --show-toplevel 2>/dev/null || pwd)"

  local candidates=(
    "$repo_root/.agents/skills/$name"
    "$repo_root/.claude/skills/$name"
    "$HOME/.agents/skills/$name"
    "$HOME/.codex/skills/$name"
    "$HOME/.claude/skills/$name"
  )

  for d in "${candidates[@]}"; do
    if [[ -d "$d" ]]; then
      echo "$d"
      return 0
    fi
  done

  echo "Error: skill '$name' not found in repo-scoped or user-scoped skill dirs." >&2
  return 1
}

PLAN_SKETCH_SKILL_DIR="$(resolve_skill_dir plan-sketch)"
python3 "$PLAN_SKETCH_SKILL_DIR/scripts/run_plan_sketch.py" "user's rough idea"

© besimple-oss, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 2 other files (scripts, references) in prompt-templates/skills/plan-sketch of besimple-oss/broccoli.

• SKILL.md
• references/prompts/plan-sketch.md
• scripts/run_plan_sketch.py

Open the folder on GitHubat commit 6cad3b9