Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add timwukp/agent-skills-best-practice --skill slack-gif-creatorgit clone --depth 1 https://github.com/timwukp/agent-skills-best-practiceWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/timwukp/agent-skills-best-practice/slack-gif-creator)<a href="https://agentmods.dev/skills/timwukp/agent-skills-best-practice/slack-gif-creator"><img src="https://agentmods.dev/badge/skills/timwukp/agent-skills-best-practice/slack-gif-creator/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/timwukp/agent-skills-best-practice/slack-gif-creator"><img src="https://agentmods.dev/badge/skills/timwukp/agent-skills-best-practice/slack-gif-creator.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00051 | $0.01983 |
| Opus 5 | $0.00026 | $0.00992 |
| Sonnet 5 | $0.00010 | $0.00397 |
| Haiku 4.5 | $0.00005 | $0.00198 |
Grade A, and why
slack-gif-creator scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 12d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
This is a copy
100% identical to slack-gif-creator — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 255 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Slack GIF Creator
A toolkit providing utilities and knowledge for creating animated GIFs optimized for Slack.
Slack Requirements
Dimensions:
- Emoji GIFs: 128x128 (recommended)
- Message GIFs: 480x480
Parameters:
- FPS: 10-30 (lower is smaller file size)
- Colors: 48-128 (fewer = smaller file size)
- Duration: Keep under 3 seconds for emoji GIFs
Core Workflow
from core.gif_builder import GIFBuilder
from PIL import Image, ImageDraw
# 1. Create builder
builder = GIFBuilder(width=128, height=128, fps=10)
# 2. Generate frames
for i in range(12):
frame = Image.new('RGB', (128, 128), (240, 248, 255))
draw = ImageDraw.Draw(frame)
# Draw your animation using PIL primitives
# (circles, polygons, lines, etc.)
builder.add_frame(frame)
# 3. Save with optimization
builder.save('output.gif', num_colors=48, optimize_for_emoji=True)
Drawing Graphics
Working with User-Uploaded Images
If a user uploads an image, consider whether they want to:
- Use it directly (e.g., "animate this", "split this into frames")
- Use it as inspiration (e.g., "make something like this")
Load and work with images using PIL:
from PIL import Image
uploaded = Image.open('file.png')
# Use directly, or just as reference for colors/style
Drawing from Scratch
When drawing graphics from scratch, use PIL ImageDraw primitives:
from PIL import ImageDraw
draw = ImageDraw.Draw(frame)
# Circles/ovals
draw.ellipse([x1, y1, x2, y2], fill=(r, g, b), outline=(r, g, b), width=3)
# Stars, triangles, any polygon
points = [(x1, y1), (x2, y2), (x3, y3), ...]
draw.polygon(points, fill=(r, g, b), outline=(r, g, b), width=3)
# Lines
draw.line([(x1, y1), (x2, y2)], fill=(r, g, b), width=5)
# Rectangles
draw.rectangle([x1, y1, x2, y2], fill=(r, g, b), outline=(r, g, b), width=3)
Don't use: Emoji fonts (unreliable across platforms) or assume pre-packaged graphics exist in this skill.
Making Graphics Look Good
What ships with it
6 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 12d ago First seen · 255 lines · 51 tokens per session scan A 2efca615ce55
slack-gif-creator is a skill published in the GitHub repository timwukp/agent-skills-best-practice (10 stars, last pushed yesterday), licensed MIT. It adds 51 tokens to every session and 1,983 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to slack-gif-creator, differing in 0 lines, and is treated as a copy.
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