Reasoning and verification
A visible plan helps follow a task but is not complete proof of the model’s internal process.
What you will learn
- Explain: the model proposes, the tool executes
- Apply the idea in an example: Reasoning and verification
- Recognize limitations and verify the exercise outcome
A visible plan helps follow a task but is not complete proof of the model’s internal process. Verify important results using evidence or calculation.
You can follow this course without an account or programming. Examples use synthetic data and AI outcomes need checking.
How it works, step by step
The model proposes, the tool executes
Tool calling produces a call request with a name and arguments. The application validates the schema, permissions and limits before execution. The result returns to context for the next step. For example, get_product_stock takes a SKU and returns a quantity; its description should explain that it does not reserve products. Distinguish empty results, validation errors, missing access and timeouts. Valid JSON does not prove the arguments are correct or the action is authorized. For external effects, also consider duplicate execution.
Fluency and truth are checked separately
A hallucination is unsupported or incorrect content presented as an answer. It can arise from missing information, ambiguity or incorrectly combined patterns. Ask for evidence and check the original document, date, units and conditions. A real citation may still fail to support the claim. Use current sources for current facts, a calculator for arithmetic, and “cannot determine” when evidence is missing. Do not treat confidence expressed in prose as a calibrated probability.
Choose by task and capabilities
Check language, context, tool calling, structured output and supported input modalities. Compare models on identical requests using the same rubric and a realistic budget. Temperature changes sampling, not truth. Reasoning effort allocates effort for compatible models and can increase time and cost; accepted values vary. Local models offer infrastructure control but require resources and maintenance. Open weights do not guarantee an unrestricted license or complete training code. Catalogs and prices change; read the current model card.
The visual map
Follow the solid arrows for the main flow. Dashed blue arrows supply data or context; dashed pink arrows show feedback or returning results. Colors and shapes distinguish models, stores, decisions and outputs. On smaller screens, scroll horizontally to follow the entire diagram.
A complete example
Two products costing 120 lei each with a 15% discount total 204 lei before shipping. External arithmetic checks the number; policy checks discount eligibility.
Try it yourself
- Separate numeric calculation from checking commercial conditions.
- Record the input, source and expected outcome before running the experiment. Use only the fictional data in the example.
- Follow the diagram stages. At every step record what information is received and produced; do not confuse intermediate output with the final outcome.
- Repeat after removing necessary information or making the input ambiguous. Check whether the system clarifies, stops or invents an answer.
- Compare with the explained solution. Keep the configuration, date, result and an explanation for differences. Change one thing and retest.
An explained solution
The result is 204 lei only when the discount is eligible; shipping remains separate. A successful exercise lets you show the connection between input, stages and outcome. When information is missing, a cautious answer is more useful than invented details. Compare more than style: check conditions, sources and operations too.
When it helps and what can go wrong
Elegant reasoning from a wrong premise remains wrong. Choose this approach when it improves a measured need. Keep a simple baseline and compare outcomes using identical inputs. One successful example does not establish reliability in every situation.
Check your understanding
Who executes a call proposed by the model?
The application or host service after validation. The model does not automatically gain unrestricted access.
Is a link in an answer enough?
No; it must support the specific claim and fit the time and circumstances.
What outcome should this exercise produce?
The result is 204 lei only when the discount is eligible; shipping remains separate.
Words to remember
- Tool calling: A structured request to use an external capability.
- Grounding: Grounding an answer in verifiable evidence.
- Reasoning effort: A model-dependent setting controlling reasoning effort.
Sources and your next step
To prepare: P05 — Structured output and tool calling