opensession: Skill for Claude Code

.agents/skills/pstack-suite/skills/principle-exhaust-the-design-space/SKILL.md

principle-exhaust-the-design-space is a skill for Claude Code from tellahq/opensession. It costs 41 tokens per session (223 once invoked), scanned A, original, MIT.

A decision-making method that compares two or three concrete prototypes or sketches before choosing a new interface or system design.

In plain words
What is it for?
Use it for unfamiliar UI interactions, architectural choices with several viable approaches, and product decisions where the experience matters.
Why use it?
It reduces the risk of committing early to an option that seems reasonable but works poorly in practice.

Skill for Claude Code

Written for Claude Code: disable-model-invocation in frontmatter. Also seen: installed under .agents/ (shared by several agents).

This is tellahq/opensession's own configuration. It tells Claude Code how to work on opensession itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything opensession configures →

Reuse

Borrowing it

Nothing to install: this file belongs to tellahq/opensession. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/tellahq/opensession/main/.agents/skills/pstack-suite/skills/principle-exhaust-the-design-space/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/tellahq/opensession

Made for: Claude Code.

Wrote 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.

agentmods badge for principle-exhaust-the-design-space

README.md
[![agentmods](https://agentmods.dev/badge/skills/tellahq/opensession/principle-exhaust-the-design-space/github.svg)](https://agentmods.dev/skills/tellahq/opensession/principle-exhaust-the-design-space)
Your own site
<a href="https://agentmods.dev/skills/tellahq/opensession/principle-exhaust-the-design-space"><img src="https://agentmods.dev/badge/skills/tellahq/opensession/principle-exhaust-the-design-space/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.

agentmods 80×15 button for principle-exhaust-the-design-space

Your own site · 80×15
<a href="https://agentmods.dev/skills/tellahq/opensession/principle-exhaust-the-design-space"><img src="https://agentmods.dev/badge/skills/tellahq/opensession/principle-exhaust-the-design-space.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 41 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 223 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00041 $0.00223
Opus 5 $0.00020 $0.00112
Sonnet 5 $0.00008 $0.00045
Haiku 4.5 $0.00004 $0.00022

Measured 7d ago against content hash 8583310d7297, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

principle-exhaust-the-design-space 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 7d 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.

Origin

Copies of this mod

6 near-identical copies found in the catalogue:

.agents/skills/pstack-suite/skills/principle-exhaust-the-design-space/SKILL.md · 22 lines

What it actually says

Exhaust the Design Space

When a novel interaction or architectural decision has no established precedent, explore several concrete alternatives before implementation. Building the wrong thing costs more than exploring three options.

The rule. When the right answer is not obvious, build 2-3 competing prototypes or sketches. Compare them side by side. Only then commit. Design it twice is this rule by another name. A second flavor of the first shape does not count.

When it applies:

  • Novel UI interactions (no prior art in the codebase)
  • Architectural choices with multiple viable approaches
  • Product design decisions where user experience depends on feel, not logic

When it doesn't:

  • Mechanical implementation where the pattern is established
  • Bug fixes or refactors with a clear target state
  • Changes where constraints dictate a single viable approach
Changes

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.

  1. 7d ago First seen · 22 lines · 41 tokens per session scan A 8583310d7297

Subscribe to this mod's changes

principle-exhaust-the-design-space is a skill published in the GitHub repository tellahq/opensession (370 stars, last pushed today), licensed MIT. It adds 41 tokens to every session and 223 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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