[Bug] advisor tool returns "unavailable" in Claude Code Desktop (Mac) while working in terminal CLI with identical settings

Environment

• Claude Code Desktop app, macOS
• Config: ~/.claude/settings.json -> "advisorModel": "opus", main model Sonnet 5

Repro

1. In a Claude Code Desktop session, have the model call advisor().
2. Call immediately returns: The advisor tool is unavailable. Do not try to use it again. with no further diagnostic.
3. Same ~/.claude/settings.json, same account, run an equivalent session in the terminal claude CLI instead -> advisor() works normally there.

Expected
advisor should work in Desktop given it is supported and correctly configured in the terminal CLI with the same settings.

Actual
advisor is unconditionally unavailable in Desktop, with a generic, non-diagnostic error, while the terminal CLI works fine under identical config.

Related

• #66784 and #67411 both report the same generic latched "unavailable" string, but for different root causes (unsupported model pairing, and concurrent-load session latching, respectively) and both are CLI-only reports. This report is specifically about a Desktop-vs-CLI platform gap, not a model-pairing or load issue.