Agentic AI Reference Architecture

Cognition · Software component

Depth-First Thought Search Controller

Software componentCognitionCognition & Memoryarc:DepthFirstThoughtSearchController

A tree search controller that recursively explores the best-scored child first, backtracking to the next-best sibling when a branch falls below a value threshold or dead-ends.

Responsibility. Pursues the most promising branch to completion with threshold-based backtracking.

Also known as: DFS, Greedy search with backtracking

Variant of Tree Search Controller abstract

When to choose. Choose when trees are deep (5+ steps), evaluation is reliable enough to trust greedy choices, or any solution suffices.

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Direct neighbourhood (hover for relationship types)

Relationships

alternative to variability

Quantitative guidance

As stated by the sources; verify before use.

Classification

Patterns
Depth-first searchThreshold pruningGreedy optimization with backtracking
Quality attributes
Performance efficiency (ISO/IEC 25010)
Risks mitigated
Breadth explosion in deep trees

Sources

  1. Ch5.2: T. Nguyen, "Tree-of-Thought (ToT) Fundamentals," in Mastering Agentic AI Systems: Guide for the NVIDIA NCP-AAI Exam, 1st ed. 2026, ch. 5.2. ISBN: 9798244538229.