Let Fate Decide

What it does

When your agent uses it

• Breaking a tie between several reasonable implementation approaches
• Handling a vague request the user casually delegated
• Drawing again when the user asks to try again with no system changes

Example prompts

• “Let fate decide how we structure the settings page.”
• “idk, whatever works for the caching approach; your call.”
• “Draw again and see if the cards suggest a different path.”

Requirements

• uv to run draw_cards.py
• Pre-approved tools (allowed-tools): Bash, Read, Grep, Glob

Workflow steps

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

1. 1Run the drawing script
2. 2The script outputs JSON for the default 12 Houses of the Zodiac spread
3. 3Read each house file and each card's meaning file to understand the draw.
4. 4Interpret the spread using the guide at {baseDir}/references/INTERPRETATION_GUIDE.md
5. 5When the task belongs to a specialized technical workflow, use
6. 6Apply the interpretation to the task at hand

What it can do on your machine

Read from SKILL.md and the folder at commit 82fe822. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves these tools, so the agent can use them without asking each time:

  • Bash
  • Read
  • Grep
  • Glob

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

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

  Shell commands in SKILL.md call:

  • uv

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

• Network

  No URLs in SKILL.md. Its commands use uv, 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

Let Fate Decide loads about 2.5k tokens when it runs, and up to ~5.5k if it reads all its reference files. Until then it costs about 129 tokens; SKILL.md has 1,194 words of instructions outside code blocks.

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

~129

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

~2.5k

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

~5.5k

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

• NotePre-approves every shell command (allowed-tools: Bash)SKILL.md

  allowed-tools: Bash, Read, Grep, Glob

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 trailofbits/skills at commit 82fe822, republished under its CC-BY-SA-4.0 licence (© trailofbits). 1,194 words, ~2,495 tokens.

name

let-fate-decide

description

Draws the 12 Houses of the Zodiac Tarot spread to inject entropy into planning when prompts are vague, ambiguous, or casually delegated. Interprets the spread to guide next steps. Use when the user says 'let fate decide', 'YOLO', 'whatever', 'idk', or other nonchalant phrases, makes Yu-Gi-Oh references, or when you are about to arbitrarily pick between multiple reasonable approaches. Prefer over asking clarifying questions when the user's tone is casual or playful rather than precision-seeking.

allowed-tools

Bash, Read, Grep, Glob

User: "I dunno, just make it work somehow"

[Draw cards]
1st House (Self): The Magician (upright), Five of Swords (reversed),
                  Ten of Pentacles (upright)

House contribution: The starting stance is resourceful and tool-rich
(Magician), but the practical details warn against combative edge-case work
(Five of Swords reversed) while still favoring maintainable craft
(Ten of Pentacles). This is one input into the overall reading; combine with
the remaining 11 houses before deciding on an approach.

© trailofbits, CC-BY-SA-4.0. 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 104 other files (scripts, references, assets) in plugins/let-fate-decide/skills/let-fate-decide of trailofbits/skills.

• SKILL.md
• agents/openai.yaml
• assets/trail-of-bits-mark.svg
• cards/cups/ace-of-cups.md
• cards/cups/eight-of-cups.md
• cards/cups/five-of-cups.md
• cards/cups/four-of-cups.md
• cards/cups/king-of-cups.md
• cards/cups/knight-of-cups.md
• cards/cups/nine-of-cups.md
• cards/cups/page-of-cups.md
• cards/cups/queen-of-cups.md
• cards/cups/seven-of-cups.md
• cards/cups/six-of-cups.md
• cards/cups/ten-of-cups.md
• cards/cups/three-of-cups.md
• cards/cups/two-of-cups.md
• … and 88 more

Open the folder on GitHubat commit 82fe822