Tool Use is models calling external functions and APIs. It sits in the Incentives dimension (INC) of the Human Behavior Taxonomy™ as element HBT-INC-0275, within the Workflow family. The core principle: models calling external functions and APIs. In incentive terms, it matters because it changes the payoff people perceive before they choose — which means it can be designed for, or exploited.
Scientific Definition
Models calling external functions and APIs.
Plain-English Definition
Models calling external functions and APIs.
Feynman Explanation
Models without tools talk. Models with tools act.
Core Principle
Models calling external functions and APIs.
Mechanisms
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Inputs (Triggers)
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Outputs (Behaviors)
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Behavioral Signature
Models without tools talk. Models with tools act.
Examples
- Function calling, code execution, web search.
- Foundation of agent capability.
Pending editorial review.
Original analysis from The Incentives Lab — how this element behaves inside real payoff structures.
Why this element matters to incentive design
The mistake with this element is treating it as irrationality. It is almost always a rational response to a payoff nobody wrote down. The mechanism underneath it operates in the Incentives dimension — what makes behavior more or less likely?. You can recognize it in the field by its signature: models without tools talk. Models with tools act. Every element in the Incentives dimension changes the perceived payoff of an action before the action happens, which is exactly where incentive design has leverage.
How it gets exploited
Left undesigned, foundation of agent capability. It is amplified whenever foundation of agent capability. Inside organizations that shows up as foundation of agent capability. The pattern is the same one Goodhart's Law describes: the measurable proxy attracts the effort, and the purpose behind it quietly loses funding.
How the Lab designs around it
The redesign move is to sandbox tools. Audit calls. Rate limit. The leverage is not in explaining the behavior to people. It is in changing what the behavior earns.
Famous Experiments
Pending editorial review.
Design Principles
- Sandbox tools. Audit calls. Rate limit.
Measurement Approaches
Pending editorial review.
Evidence
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The Perverse Incentive Lens™
How this behavior is exploited — and how to redesign around it.
- Sandbox tools. Audit calls. Rate limit.
Pending editorial review.
Pending editorial review.
Interactive Mini Network
Click any neighbor to re-center the graph and follow the threads of connection.
Knowledge Graph Neighbors
Auto-linked to the rest of the Human Behavior Taxonomy by family, domain, dimension, and shared keywords.
AI system that takes actions to achieve goals, often across tools.
Designing processes from scratch around AI capability.
The relationship between inputs and outputs changes.
How much input the model can process at once.
Underlying data distribution changes over time.
Vector representation of content for similarity and search.
Evaluation suites that no longer reflect real-world conditions.
Systematic testing of model quality, safety, and capability.
Models learning from examples in the prompt.
How much delay the user experience tolerates.
Train a smaller model to imitate a larger one.
Performance degradation as real-world data shifts.
Where Tool Use is cited in the corpus
Essays, field guides, and diagnostics from The Incentives Lab that apply this element.
- Field guideIncentives: definition, types, examples
The parent field guide for this element.
- ReferenceThe laws of incentives
Goodhart, Campbell, and the Cobra Effect.
- EssayAI Agents Inherit Your Incentives
How this element propagates into automated systems.
- ReferenceThe incentive glossary
Definitions for every mental model, bias, and fallacy in the corpus.
- ReferenceThe Periodic Table of Human Behavior
The full 1,267-element map this page belongs to.
Questions about Tool Use
- What is Tool Use?
- Tool Use is models calling external functions and APIs. It sits in the Incentives dimension (INC) of the Human Behavior Taxonomy™ as element HBT-INC-0275, within the Workflow family. The core principle: models calling external functions and APIs. In incentive terms, it matters because it changes the payoff people perceive before they choose — which means it can be designed for, or exploited.
- What is an example of Tool Use?
- Foundation of agent capability. The Incentives Lab catalogs everyday, organizational, and historical instances of this element on its Human Behavior Taxonomy™ page (HBT-INC-0275).
- How is Tool Use exploited?
- Foundation of agent capability.
- How do you design around Tool Use?
- Sandbox tools. Audit calls. Rate limit.
- Which behavioral dimension does Tool Use belong to?
- Tool Use is classified in the Incentives dimension (INC) of the Human Behavior Taxonomy™, family "Workflow", class "AI-Behavioral Coupling". Its permanent identifier is HBT-INC-0275 and its evidence grade is C.