Other vs Testing · both proven

internal-comms vs test-driven-development

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.

internal-comms

A set of resources to help me write all kinds of internal communications, using the formats that my company likes to use. Claude should use this skill whenever asked to write some sort of internal communications (status reports, leadership updates, 3P updates, company newsletters, FAQs, incident reports, project updates, etc.).

Category: Other
Source: anthropics/skills · 182,147 stars
License: Not stated
Proof model: claude-opus-5-5
Brief: “Write this week's status update for the Checkout Redesign project as a single HTML page for the leadership channel. Facts to use: the new cart page shipped to 10% of traffic on Tuesday; conversion in the test group is up 2.1% so far; the payments team is two days late on the saved-cards work; a legal review of the new terms copy is still open; launch to 100% is planned for the 30th if the saved-cards work lands by Friday. Keep it short enough to read in a minute.”
Skill commit: dbd4588

test-driven-development

Use when implementing any feature or bugfix, before writing implementation code

Category: Testing
Source: obra/superpowers · 301,947 stars
License: MIT
Proof model: claude-opus-5-5
Brief: “Implement a function that parses a cron expression (the standard five fields) and returns the next run time after a given date, in TypeScript. Present the work as a single HTML page with two columns: the test file on the left and the implementation on the right, each in a code block, with a short note at the top on the order you did things in and anything you decided not to support.”
Skill commit: bb92a77

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 internal-comms or alternatives to test-driven-development.