A skill exists to wrangle determinism out of a stochastic system.

Predictability

— the agent taking the same

process

every run, not producing the same output — is the root virtue; every lever below serves it.

Bold terms

are defined in

GLOSSARY.md

; look them up there for the full meaning.

Invocation

Two choices, trading different costs:

A

model-invoked

skill keeps a

description

, so the agent can fire it autonomously

and

other skills can reach it (you can still type its name too). It contributes to

context load

— the description sits in the window every turn. Mechanics: omit

disable-model-invocation

, and write a model-facing description with rich trigger phrasing ("Use when the user wants…, mentions…").

A

user-invoked

skill strips the description from the agent's reach: only you, typing its name, can invoke it — and no other skill can. Zero context load, but it spends

cognitive load

:

you

are the index that must remember it exists. Mechanics: set

disable-model-invocation: true

; the

description

becomes human-facing — a one-line summary, trigger lists stripped.

Pick model-invocation only when the agent must reach the skill on its own, or another skill must. If it only ever fires by hand, make it user-invoked and pay no context load.

When user-invoked skills multiply past what you can remember, that piled-up cognitive load is cured by a

router skill

one user-invoked skill that names the others and when to reach for each. Writing the description A model-invoked description does two jobs — state what the skill is, and list the branches that should trigger it. Every word increases context load , so a description earns even harder pruning than the body: Show more Installs 1.7K Repository mattpocock/skills GitHub Stars 132.4K First Seen Today Security Audits Gen Agent Trust Hub Pass Socket Pass Snyk Pass