The Fable 5 advisor tool is always unavailable, preventing its use in any session.
The Fable 5 advisor tool is always unavailable, preventing its use in any session.
Problem statement normalized from the linked evidence
CANDIDATE VIEW · NOT A PUBLISHED OPPORTUNITY
01
Qualification checklist
Gate decision: Aug 15, 2026
×
At least 3 independent users2 / 3
NOT MET
✓
At least 2 independent discussions2 / 2
MET
✓
At least 1 supporting signal1 Workarounds · Persistence
MET
02
Observed signals
Users2
Discussions2
Mentions2
Active days2
Source coverageGitHub
TrendUNKNOWN
First seenJul 02, 2026
Last seenJul 09, 2026
Why the gate is holding
Fewer than 3 independent users
Competition research, commercial scoring, and Build Gap analysis do not run until this gate passes.
03
Source evidence
2 evidence records
github · HIGH · Jul 09, 2026
Advisor (Fable 5) returns "unavailable" whenever the transcript contains any prior tool call — one Bash(ls) suffices; Opus advisor immune
## Summary The server-side advisor tool with `advisorModel: "fable"` (`claude-fable-5`) returns `advisor_tool_result_error` with `error_code: "unavailable"` **whenever the session transcript contains at least one prior tool call — any tool, e.g. a single `Bash(ls)` or one `Read`**. With zero prior tool calls the identical configuration succeeds. Switching only `advisorModel` to `opus` makes the same tool-call-then-advisor sequence succeed. Since the advisor's documented purpose is to be consulted *after* orientatio…
[BUG] Advisor always "unavailable" with Fable 5 advisor (Opus 4.8 main) across all sessions (v2.1.198)
### Preflight Checklist - [x] I have searched [existing issues](https://github.com/anthropics/claude-code/issues?q=is%3Aissue%20state%3Aopen%20label%3Abug) 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? With the advisor set to Fable 5, the advisor tool returns `The advisor tool is unavailable. Do not try to use it again.` on the very first advisor call — in **every** session, r…