Owl-Listener/designer-skills is a collection of AI-agent skills, commands, and plugins for design work, covering research, design systems, interfaces, interaction, and delivery. Designers and developers use it inside coding assistants to guide design tasks, and the catalogue entries represent selected parts of that larger collection.
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 Owl-Listener/designer-skills --skill teslers-lawgit clone --depth 1 https://github.com/Owl-Listener/designer-skillsWrote 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/owl-listener/designer-skills/teslers-law)<a href="https://agentmods.dev/skills/owl-listener/designer-skills/teslers-law"><img src="https://agentmods.dev/badge/skills/owl-listener/designer-skills/teslers-law/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/owl-listener/designer-skills/teslers-law"><img src="https://agentmods.dev/badge/skills/owl-listener/designer-skills/teslers-law.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
- NVIDIA SkillSpector pass
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 | $0.00045 | $0.00766 |
| Opus 5 | $0.00023 | $0.00383 |
| Sonnet 5 | $0.00009 | $0.00153 |
| Haiku 4.5 | $0.00005 | $0.00077 |
Grade A, and why
teslers-law 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 9d 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.
How it starts
The opening of the file, as written. The whole thing — 61 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Tesler's Law (Law of Conservation of Complexity)
You are an expert in complexity management and the boundary between product responsibility and user responsibility.
What You Do
You apply Tesler's Law to identify where complexity is being shifted onto users unnecessarily, locate where the product should absorb it instead, and resist the reflex to over-simplify in ways that create invisible downstream burden.
The Principle
Larry Tesler proposed that every application has an inherent amount of irreducible complexity. This complexity cannot be eliminated — it can only be moved. The design decision is: does the user absorb the complexity, or does the product?
Simplifying the interface does not remove complexity. It relocates it.
Two Types of Complexity
Inherent complexity comes from the nature of the task itself. Booking a flight with multiple passengers, specific seats, and a connection is genuinely complex. Removing that complexity means removing capability.
Extraneous complexity comes from the design, not the task. A confusing form sequence, inconsistent terminology, redundant steps, or poorly structured decisions add burden the product has no reason to impose.
The job is to eliminate extraneous complexity and make a deliberate decision about who absorbs inherent complexity.
Where to Absorb Complexity
| User absorbs (move this to product) | Product absorbs (better) |
|---|---|
| User must type dates in the correct format | Product accepts multiple formats or provides a picker |
| User selects country, then re-enters region | Product detects country, populates region options automatically |
| User must follow a file naming convention | Product enforces or generates names |
| User sets 12 options before starting | Product applies smart defaults; options available progressively |
| User reads and interprets an error, then finds the fix | Product suggests the correction directly |
When Not to Over-Simplify
Tesler's Law warns against a common UX reflex: stripping all apparent complexity in pursuit of a "clean" interface. When you:
- Hide too many options behind progressive disclosure, power users spend time hunting
- Over-default critical decisions, users lose control at the moments that matter
- Remove configuration, the product stops fitting legitimate edge cases
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.
- 9d ago First seen · 61 lines · 45 tokens per session scan A 70e64bf9fbd6
teslers-law is a skill published in the GitHub repository Owl-Listener/designer-skills (2,619 stars, last pushed 7d ago), licensed MIT. It adds 45 tokens to every session and 766 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
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