fable5

Use before any approved Mythos-style defensive cybersecurity run, or when reviewing a Fable/Mythos security workflow. Requires authorization, bounded targets, private evidence handling, independent validation, and a patch/report owner before the model explores vulnerabilities.

Stop Claude Fable 5 from over-planning, re-deriving settled facts, or listing options it won't pursue. Use in interactive sessions where turns feel slow on simple asks, or agentic sessions at high/xhigh effort where the model gathers more context than the task needs.

Keep Claude Fable 5 running to completion in unattended pipelines -- no stalling on a stated intent without the matching tool call, no mid-run permission questions, no self-imposed session splits from context-budget worry. Use for overnight runs, scheduled jobs, and CI agents where nobody is watching to type "continue".

Pick and re-evaluate the output_config.effort level for a Claude Fable 5 workload. Use when designing a pipeline that mixes routine and hard tasks, when a call feels slow or expensive for what it's doing, or when porting an Opus 4.7/4.8 harness that defaulted to xhigh.

Bind every progress claim Claude Fable 5 makes during a long or autonomous run to an actual tool result from that session. Use for multi-hour agents, overnight pipelines, CI runs, or any workflow where a status update has previously claimed work that wasn't actually done.

Maintain a file-based lesson memory that Claude Fable 5 reads and updates across sessions. Use for recurring agents (daily jobs, long projects, team assistants) where the same correction keeps being re-made, or when bootstrapping a new agent from past session history.

Keep Claude Fable 5's diffs mapped one-to-one to the request -- no unrequested refactors, speculative abstractions, or defensive error handling for states that can't occur. Use in code review and any coding session where the diff comes back larger than the ask, especially at high or xhigh effort.

Make Claude Fable 5's final report readable to someone who saw none of the work. Use for long agentic sessions, overnight runs, and multi-tool tasks whenever summaries come back as arrow-chain shorthand, invented abbreviations, or references to reasoning the reader never saw.

Write and review Claude Fable 5 API calls and prompts so a safety-classifier refusal degrades gracefully instead of dead-ending. Use whenever adding a new claude-fable-5 call, reviewing security/red-team/bio/ML-adjacent workloads that are refusal-prone, or debugging a request that silently returned no content.

Stop Claude Fable 5 from taking actions nobody asked for -- applying a fix when only asked to diagnose, restarting a service, creating a backup branch, editing a config on a hunch. Use for ops/debugging sessions, production-adjacent work, and shared environments where the cost of an unrequested change is high.

Check finished work with a fresh-context subagent instead of self-critique when using Claude Fable 5. Use when designing multi-agent harnesses, verifying long-run output, or any time self-review keeps missing its own mistakes -- the maker should not grade its own work.