[BUG] Tab autocomplete completes skill names to dash form, losing argument-hint rendering vs. colon form

Summary

Tab autocomplete for slash commands matches the skill directory basename (dash form) instead of the name: field declared in SKILL.md frontmatter. When a skill uses a colon-separated name: (e.g. t1k:git), the two forms behave inconsistently:

| Form | How produced | Argument-hint shown? |
|---|---|---|
| /t1k:git | typed manually | ✅ yes |
| /t1k-git | inserted by Tab | ❌ no |

Both forms execute the same skill, but only the colon form triggers argument-hint rendering and parameter suggestion UI. This makes Tab autocomplete a discoverability regression: it actively hides hints the user would get by typing manually.

Environment

• Claude Code: 2.1.145
• Node: v24.13.0
• Platform: Linux (also reproduced by team on macOS; Windows blocked by separate filesystem constraint, see below)

Repro

1. Create a skill with colon-namespaced name: in frontmatter:

``
~/.claude/skills/t1k-git/SKILL.md
---
name: t1k:git
description: Git operations with conventional commits.
argument-hint: <cm|cp|pr|merge> [args...]
---
``

(Directory MUST be dash because : is hostile to Windows NTFS and shell globs — see "Why two forms" below.)

1. In the Claude Code prompt, type /t1k: and press <kbd>Tab</kbd>.

1. Expected: autocomplete inserts /t1k:git and shows the argument-hint parameter suggestions.

1. Actual: autocomplete inserts /t1k-git (the filesystem directory name). No argument-hint is displayed. Typing /t1k:git by hand instead works correctly.

Root cause hypothesis

The slash-command completion engine globs ~/.claude/skills/*/ directory names rather than reading the name: field from each SKILL.md. The dispatcher that runs the skill DOES read name: (both forms resolve), but the completion candidate list is filesystem-driven.

Why we use two forms (and why "just rename the directory" isn't viable)

The TheOneKit ecosystem (~326 skills across 9 repos, used by ~50 internal developers) enforces this rule:

• Filesystem directory uses dash (t1k-git/) — because : is reserved on Windows NTFS (alternate data streams), breaks shell globs (ls *:*), and confuses many tools.
• SKILL.md name: uses colon (t1k:git) — because that is how the Claude Code slash UI renders namespaced skills, and it's the form documented in the skills guide examples for namespaced commands.

The two slugs are byte-identical after -↔: conversion. Renaming the directory to use : is not an option for cross-platform kits.

Suggested fix

Change the autocomplete resolver to enumerate completion candidates from each SKILL.md's name: frontmatter field (with fallback to directory basename when name: is missing). The execution path already handles both forms correctly — only the completion list needs updating.

Rough pseudocode for the change:

// Before (hypothetical):
const candidates = fs.readdirSync(skillsDir);

// After:
const candidates = fs.readdirSync(skillsDir).map(dir => {
  const skillMd = path.join(skillsDir, dir, 'SKILL.md');
  const fm = parseFrontmatter(skillMd);
  return fm.name || dir;  // prefer declared name, fall back to dirname
});

Related issues (all closed, but adjacent)

• #9768 — Tab autocomplete for slash commands broken in v2.0.0+ (VSCode extension)
• #20667 — Keep argument-hint visible while typing
• #18574 — argument-hint not included in Skill tool metadata for agent-to-agent invocation
• #43401 — Feature: Support argument-hint in Skills YAML frontmatter

None of those track this specific dash/colon completion mismatch.

Impact

• Every skill that uses colon-namespaced name: is affected (TheOneKit alone has ~326 such skills).
• Affects discoverability for new users: Tab inserts the form WITHOUT hints, training people away from the form that has them.
• No local workaround exists — Claude Code is closed-source, settings.json has no autocomplete hook, ~/.claude/keybindings.json only remaps keys, and :-named symlinks don't work cross-platform.

Workaround (until fixed)

Type the colon form manually and don't accept Tab completions for skill names. Painful at scale.