
Claude Fable 5 vs Opus 5: which model should your AI agents use?
Fable 5 or Opus 5? Choose by mission difficulty and cost per successful task — not by putting Anthropic’s strongest model everywhere.
An AI agent is only useful when it can act on real work with real guardrails: a scoped role, the right permissions, durable memory, and a human approval gate where it matters. Without that frame, “agentic” mostly means an unsupervised script with a chat interface.
These guides cover how to define agent roles, how to give agents the context they need without giving away the workspace, and how documentation becomes the memory that makes agents reliable over time.
Read the agents guide in the docs