Feature request: config option to exclude skill scan locations and/or support namespaced skill names (e.g. `ck:name`)

[rednam-ntn]

Feature Request: Allow excluding skill scan locations and/or support namespaced skill names (e.g., ck:name)

Summary

Two related quality-of-life improvements for skills loading in GitHub Copilot CLI:

1. A config option to exclude specific skill scan directories (e.g., ignoredSkillsLocations)
2. Support for namespaced skill names containing : (colon), such as ck:agent-browser

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Problem

Copilot CLI auto-scans several hardcoded directories for skills, including ~/.claude/skills and ~/.agents/skills. These paths are also used by other AI tools (Claude Code, OpenCode, etc.) which have more permissive skill name validation — they accept names with colons, like ck:agent-browser.

When skills stored in ~/.claude/skills use the ck: namespacing convention, Copilot CLI fails to load them with errors like:

✖ The following skills failed to load:
  • ~/.claude/skills/agent-browser/SKILL.md: name: Skill name must contain only letters, numbers, hyphens, underscores, dots, and spaces
  • ~/.claude/skills/code-review/SKILL.md: name: Skill name must contain only letters, numbers, hyphens, underscores, dots, and spaces
  ... (repeated for every skill in the directory)

This produces noisy errors on every Copilot CLI startup — even though the user has no intention of using those skills in Copilot CLI. The errors cannot currently be suppressed:

• disabledSkills in config.json works by skill name, but since these skills fail to parse, the name is never registered — so disabledSkills cannot silence the errors.
• There is no config key to exclude a directory from scanning.

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Proposed Solutions

Option A — ignoredSkillsLocations config key (preferred)

Add a config.json key that lists directories to exclude from the auto-scan:

// ~/.copilot/config.json
{
  "ignoredSkillsLocations": [
    "~/.claude/skills",
    "~/.agents/skills"
  ]
}

This gives users full control to opt out of auto-scanning shared directories they use for other tools.

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Option B — Allow : in skill names (namespace support)

Relax the skill name validation regex to accept colons, enabling namespaced names like ck:agent-browser:

Current regex (inferred): ^[a-zA-Z0-9\-_. ]+$
Proposed regex: ^[a-zA-Z0-9\-_. :]+$

This would allow skills shared across multiple AI tools to use a common namespacing convention without modification.

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Option C — Both (ideal)

Both options are complementary:

• Option A helps users who want clean separation between tool-specific skill directories.
• Option B helps users who want shared skill libraries with namespaced names to work uniformly across tools.

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Current Workaround

Users must either:

• Duplicate and rename skills into ~/.copilot/skills with modified names (lossy, requires manual sync)
• Accept the noisy startup errors with no way to suppress them

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Environment

• Platform: macOS
• Tool: GitHub Copilot CLI
• Related auto-scanned paths: ~/.claude/skills, ~/.agents/skills, ~/.copilot/skills