Intermediate · Systems

Context-Aware Tool Selection

Visual diagram · (in preparation) · Math · (in preparation) · Worked example · 3 difficulty levels.

TL;DR. Exposing and choosing tools dynamically based on the current task phase rather than presenting every tool at every step.

Technical Definition

Exposing and choosing tools dynamically based on the current task phase rather than presenting every tool at every step.

How it works

Large tool catalogues hurt agents twice: schemas consume tokens, and near-duplicate options increase selection errors. Context-aware tool selection narrows the visible set using the task phase, prior tool results, the user's permissions, and semantic search over tool descriptions — often retrieving a handful of relevant schemas from a registry rather than inlining hundreds. It also enforces safety, since a tool that is not exposed cannot be invoked by a prompt-injected instruction.

Related Concepts

• Agentic Context Strategies — The repertoire of techniques for filling an agent's window: retrieval, summarization, scratchpads, sub-agents, and offloading to files.
• Context Management — The engineering practice of controlling what goes into a model's context window, in what order, and at what cost.
• Agent Capabilities — The concrete set of actions an agent can perform — the tools, APIs, and side effects available to it.
• Adaptive Agent Context — Context that reshapes itself at runtime based on the task phase, difficulty, and what the agent has already learned.