Skill Creator Primer

Note: If your environment does not have the skill-creator skill: Stop and ask the user to install skill-creator@claude-plugins-official (running /plugin marketplace add anthropics/claude-plugins-official first if that marketplace isn't registered) before proceeding; they may alternatively clone https://github.com/anthropics/skills and link its skills directory to their local skills directory.

Route to an entry point by the task in front of you (which-one routing per "Routing when branches multiply", not a content index):

• Creating a new skill -> start at "Capture Intent from Conversation" and work forward.
• Editing an existing skill -> the sections covering what you're changing, then the "Self-Review Protocol".
• Reviewing a skill, or a diff to one -> "Reviewing a Skill".
• Tuning a description or its triggering -> "Writing Effective Descriptions".

Predictable Process, Not Identical Output

A skill wrangles determinism out of a stochastic system where applicable. What it makes predictable is the process - the agent taking the same steps each run - not the output. A brainstorming skill should predictably diverge: its tokens vary, its behaviour doesn't. This is the lens for the rest of this primer: triggering, structure, steering, and pruning are all levers on process consistency, and cost and maintainability follow from it. Judge any change by whether it makes the agent behave more consistently, given what that particular skill is for.

Track Each Step as a Task

Before you create, update, or review a skill, create a task (todo) for each step of the work - the primer sections you'll apply, plus a self-review pass - then work them to completion, marking each done as you go. This is the primer's own defence against premature completion: with the finish line in view, the agent tends to make the visible edit and skip the review. Tracked tasks keep the whole process in front of you so none of it gets dropped. Scale the ceremony to the change: substantial skill work warrants a task per step; a trivial edit still earns its description update, a trigger-conflict check, and a self-review pass, tracked or not.