Agent Skills: claude-five-prompting-guide

Guidelines for prompting and building context for Claude 5 generation models (Sonnet 5, Opus 5, Fable 5), based on Anthropic's official guidance from July 2026. Use this skill whenever the user asks how to prompt Claude 5 models, wants to write or review a system prompt, CLAUDE.md, skill, or agent harness targeting these models, mentions "unhobbling", "unknowns", "blind spot pass", "context engineering", or asks why an agentic task came back wrong despite detailed instructions. Also use it when auditing existing prompts or rules for over-constraint, or when migrating prompts written for Claude 4-era models. When invoked with file path arguments, audit those files against the guide (prefer delegating the audit to a read-only sub-agent and returning only findings).