[BUG] Agents in .claude/agents/ not appearing in @agent autocomplete after v2.1.14

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Claude Code Version: 2.1.15

OS: macOS Darwin 24.6.0

Description:
Newly created agent files in .claude/agents/ directory do not appear in the @agent autocomplete menu, while previously existing agents in the same directory continue to work.

Expected Behavior:
All valid agent files in .claude/agents/ should appear in the @agent autocomplete menu after restart.

Workaround Attempted:
None successful. Verified file encoding (UTF-8), YAML format, and file permissions all match working agents.

What Should Happen?

Only agents that existed before a certain point appear when typing @agent. New agents with valid format are not discovered. Would expect any agent found in the /agents list should be found in @agent autocomplete menu. This worked in a previous version. Not sure which update caused the issue, but 2.1.14 seemed to have some changes related to @ autocomplete.

Error Messages/Logs

Diagnostic Information:
  - Both working and non-working agent files have identical YAML frontmatter structure
  - Files are in the same directory with same permissions
  - validate-agent.sh passes for the new agent
  - No errors in ~/.claude/debug/latest related to agent loading
  - Debug log shows "Total plugin agents loaded: 0"
  - Multiple restarts do not resolve the issue

Potentially Related Changes:
  This may be a regression from v2.1.14 changelog entries:
  - "Fixed @ symbol incorrectly triggering file autocomplete suggestions in bash mode"
  - "Fixed @-mention menu folder click behavior to navigate into directories instead of selecting them"

Steps to Reproduce

1. Have existing working agents in .claude/agents/ (e.g., program-documenter.md)
2. Create a new agent file with identical YAML frontmatter format (e.g., legacy-table-analyzer.md)
3. Restart Claude Code
4. Type @agent to trigger autocomplete
5. New agent does not appear; existing agents do

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.15 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_