Tools

Provides a sequential_thinking tool that guides the model to break complex problems into revisable, branching steps. Good for planning, analysis and tasks that need careful iteration. Official MCP reference server.

Official Anthropic plugin that solves competition math such as IMO and Putnam problems, with adversarial checks by an independent verifier that only sees the clean proof. Gives up explicitly rather than bluffing when unsure, and outputs LaTeX/PDF once verified.

Give it a person's name or a vague need and it researches and distills their mental models, decision style and voice into a callable persona skill (e.g. Munger, Feynman, Jobs) to aid analysis and decisions. Works with Claude Code, Codex and other agents.