Design vs Testing · both proven

crypto-protocol-diagram vs writing-guidelines

Both skills were run through Claude twice: once on a fixed brief without the skill, once with it. The briefs differ because each is written for the job the skill claims to do, so compare each skill against its own baseline, then decide which difference matters for your work. They are in different categories, so this is a choice of job, not a head-to-head on the same job.

crypto-protocol-diagram

Extracts protocol message flow from source code, RFCs, academic papers, pseudocode, informal prose, ProVerif (.pv), or Tamarin (.spthy) models and generates Mermaid sequenceDiagrams with cryptographic annotations. Use when diagramming a crypto protocol, visualizing a handshake or key exchange flow, extracting message flow from a spec or RFC, diagramming a ProVerif or Tamarin model, or drawing…

Category: Design
Source: trailofbits/skills
License: Other
Proof model: claude-opus-5-5
Brief: “Draw the message flow of this login protocol as a single HTML page with an SVG sequence diagram, and note any weaknesses. 1. Client sends username to server. 2. Server replies with a random 16-byte nonce and the user's salt. 3. Client computes H = SHA-256(salt || password) and sends HMAC-SHA256(key=H, msg=nonce). 4. Server looks up stored H, computes the same HMAC and compares. 5. On success the server returns a session token valid for 30 days.”
Skill commit: 2be6433

Without the skillWith crypto-protocol-diagram

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Without, runWith crypto-protocol-diagram, run3 independent runs per side, none selected by hand.

Download the with-skill page

writing-guidelines

Review docs/prose for Writing Guidelines compliance. Use when asked to "review my docs", "check writing style", "audit prose", "review docs voice and tone", or "check this page against the writing handbook".

Category: Testing
Source: vercel-labs/agent-skills
License: Not stated
Proof model: claude-opus-5-5
Brief: “Review and rewrite this getting-started page for Pipewell, a data pipeline CLI. The draft opens with two paragraphs of company history, mixes 'you' and 'the user', buries the install command in the fourth paragraph, uses passive voice throughout, and ends without a next step. Write the improved page as a single HTML document, followed by a short list of what you changed and why.”
Skill commit: 063bee9

Without the skillWith writing-guidelines

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Without, runWith writing-guidelines, run3 independent runs per side, none selected by hand.

Download the with-skill page

We don’t pick a winner for you: the pages are the evidence. Both proofs can be repeated with the brief, model and commit shown above. See alternatives to crypto-protocol-diagram or alternatives to writing-guidelines.