- Separate explanations from verified results.
- Trace a tool call and observation.
- Compare workflows and agent loops.
- Design stopping conditions.
- Choose deterministic checks for exact requirements.
Before you begin
Understand a model's role inside an application and training versus inference.
Reasoning still needs evidence
Planning a study afternoon involves deadlines, available time, and priorities. We may call this reasoning because the task combines relationships and choices. Some models spend additional computation on such work, but visible explanations are not guaranteed records of every internal operation.
Ask for evidence you can inspect: a calculation, assumptions, concise justification, or testable result. A long explanation can contain a wrong step. Evaluate the link between evidence and conclusion rather than treating verbosity as intelligence.
A model can use another program for a subtask. A real calculator result provides stronger arithmetic evidence than a generated number, provided its inputs and interpretation are correct.
Tools are controlled software operations
A tool is a function or service the application makes available, such as searching documents, calculating an expression, or reading a sensor. An API defines how software requests operations and receives results.
Typically the model proposes a structured request, the host validates it, the tool executes, and an observation returns. The model can use that observation in its response. The application controls access; generated words do not grant permission to read files or move motors.
A calendar-reading tool might return available periods for a study plan. Creating calendar events is a separate action with an external effect. The user's intent should determine which actions are allowed.
Goal → proposed tool call → application checks request
→ returned observation → next-step evaluationFixed sequences and agent loops
A fixed workflow follows a predefined sequence: read a document, summarize it, check length, save a draft. It can contain a model without letting that model decide every next action. Predictable tasks often benefit from this structure.
An agent gives a model some ability to select actions toward a goal. It may gather information, inspect results, revise a plan, and continue. The term is used inconsistently: ask what actions it can select, what state it receives, and what ends the loop.
Autonomy adds flexibility and opportunities for error. A wrong search can lead to a wrong conclusion and then an inappropriate action. Bound tools and attempts to the task. Stop when evidence is missing instead of inventing progress.
Build an article-checking workflow
The goal is checking our 11-minute article limit. A program counts words and code lines. If the estimate is too high, a model proposes edits. The program measures again, and a reviewer checks whether the cuts preserved the lesson.
The model helps rewrite; the deterministic counter applies the agreed formula consistently. Asking a model merely to announce eleven minutes does not measure the text. This division of work makes success inspectable.
Define success as a draft inside the limit with its example and quiz intact. Stop after a small number of unsuccessful revisions and narrow the scope. Saving a draft is different from publishing it; permissions should reflect that distinction.
Carry the principle into robotics
A robot model might propose forward movement, while the controller enforces speed limits, valid sensor readings, and stop behavior. A persuasive generated explanation should not override a physical constraint.
Tools can return untrusted content, including documents with command-like text. Treat that content as source data, not authority to change the task. The Google ML glossary provides terminology for comparing models and their surrounding systems.
Important terms
- Tool
- An operation the application permits a model to request.
- API
- A defined software interface.
- Agent
- A system in which a model selects actions toward a goal.
- Observation
- Information returned by a tool or action.
- Deterministic check
- A check with defined behavior for the same relevant input.
- Stopping condition
- A criterion ending a workflow.
Mini project: Specify a study-planning agent
- Set a goal: draft a plan using a supplied timetable.
- Permit reading the timetable, calculating durations, and drafting.
- Require no overlapping sessions and no exceeded time allowance.
- Specify what happens when information is missing.
- Finish with a workflow another person can run and audit manually.
Common mistakes and debugging
- Assuming tools ran because an answer names them: inspect observations.
- Using endless loops: define success and failure exits.
- Letting generated instructions grant permissions: enforce access in software.
- Replacing arithmetic checks with confident text: calculate directly.
Independent challenge
Add a revision step when a session overlaps class. Record the conflict and verify the correction.
Check your understanding: 10 questions
What executes a tool request?
How does an agent differ from a fixed workflow?
Why count words with a program?
Does calendar reading authorize event creation?
What constrains motor commands?
In your own words, what does “Tool” mean?
In your own words, what does “API” mean?
In your own words, what does “Agent” mean?
In your own words, what does “Observation” mean?
In your own words, what does “Deterministic check” mean?
Quiz answers
Reveal all 10 answers after your attempt
- The host application and tool, after required validation.
- It can choose some next actions rather than following only a predefined sequence.
- It applies a consistent formula to the actual text.
- No. They are separate actions with different effects.
- Tested controller limits, valid inputs, and stop behavior.
- An operation the application permits a model to request.
- A defined software interface.
- A system in which a model selects actions toward a goal.
- Information returned by a tool or action.
- A check with defined behavior for the same relevant input.
Summary
Tools provide observable operations; agents add action selection. Combine model judgment with explicit permissions, measurable checks, and stopping conditions.
Continue learning
AI08 sets practical expectations for AI capabilities and limitations.
- Advanced Prompting and Multi-Step AI Workflows
- AI Agent vs Chatbot: Capabilities and Limitations
- How Artificial Intelligence Changes Robotics
- Build a Complete Computer-to-Arduino AI System
Sources and further reading
Prepared 2026-09-18. Draft — conceptual workflow; no external or hardware execution claimed
Extra reading & source documents
Optional reading alongside the lessons. These sources do not add to your course lesson count.
- Meet Rosalind WorkbenchSupplied research-preview article
- Automating repetitive work with CodexSupplied OpenAI case study
- GPT-6 Astra: supplied introductionSupplied launch text