name-format

What it catches#

Skill name is not lowercase letters, digits and single hyphens.

A skill name with uppercase letters, spaces, underscores, dots, or a hyphen at the start, end or doubled. The Agent Skills spec allows lowercase letters, digits and single hyphens. Lowercase letters outside ASCII (such as é) are a warning rather than an error: the spec accepts them, the Claude API and claude.ai do not. The message suggests a valid name when it can.

Why it matters#

The Claude API and claude.ai accept only a-z, 0-9 and hyphens. The Agent Skills spec also allows lowercase Unicode letters, which is reported as a warning.

---
name: PDF_Processing
description: Extract text and tables from PDF files. Use when working with PDFs or forms.
---

---
name: pdf-processing
description: Extract text and tables from PDF files. Use when working with PDFs or forms.
---

How to fix#

Use the name from the message (pdf-processing for PDF_Processing) and rename the folder to match. Lowercase everything, replace spaces, underscores and dots with one hyphen, and trim hyphens from the ends.

asitis can propose this edit. asitis lint --fix-preview prints a unified diff that git apply accepts, and the suggest_fixes MCP tool returns the same diff; nothing is written to disk by either. The fix for this rule needs review before you apply it, because it changes or removes content.

Suppress or configure#

For one finding, put a comment on the line above it. The reason after -- is optional but worth writing:

<!-- asitis-disable-next-line name-format -- why this one is fine -->

For a whole file:

<!-- asitis-disable-file name-format -- why this file is an exception -->

For every file, turn it off or change its severity in .asitisrc.json:

{ "rules": { "name-format": "off" } }

A .asitisrc.json overrides entry limits a change to some paths, and a baseline (asitis lint --format json --write-baseline) accepts today's findings so only new ones fail the build.

Source#

Claude API docs: Agent Skills overview, read on 14 October 2026.