Understand what a skill teaches
Separate instruction, tool, and result before automating.
What it is
A skill is a reusable procedure that guides an agent through a task. In the video analogy, the result is the pancake, the agent is the cook, and the skill is the recipe. The file records decisions you don’t want to explain again with every request.
Why learn
Without a procedure, the agent has to fill in gaps: size, format, sources, and quality criteria. Recording these choices reduces avoidable variation. This doesn’t make generation infallible: different ingredients and unavailable tools still change the outcome.
Key concepts
- Input: the received material.
- Process: the actions and decisions.
- Output: the delivered artifact.
- Acceptance: evidence that the delivery is fit for purpose.
What it is
A prompt asks for something in this interaction. A skill stores a specialized procedure. AGENTS.md records durable project guidance. A tool carries out a concrete capability, like reading a file or querying a service. These pieces complement each other.
Why learn
When everything goes into the global rule, details of one task start influencing unrelated tasks. When everything stays in the prompt, you repeat instructions. Separating roles helps you find the correct place for each correction.
Key concepts
- Prompt: intention and execution data.
- Skill: a reusable method.
- AGENTS.md: project conventions.
- Tool: capability and access.
What it is
The best first candidate is a frequent task with a definition of “good” that you can demonstrate. It doesn’t need to be complex. A video description, a text review, or a short report already lets you learn the whole cycle.
Why learn
Starting with “manage my business” mixes planning, writing, accounting, and publishing. You can’t locate the mistake. A smaller task produces an assessable artifact and gives faster feedback before connecting important systems.
Key concepts
- Frequency: how many times it repeats.
- Cost of the error: what a failure causes.
- Observability: how to recognize success.
- Scope: where the task ends.
What it is
The contract describes what needs to be delivered, what will be produced, and what happens when information is missing. In our lab, the CSV contains date, channel, and value. The output includes observed period, total, totals by channel, and pending items.
Why learn
Missing data should not turn into silent assumptions. If “value” doesn’t exist, the skill can’t calculate revenue. A useful response identifies the missing field, stops only the dependent step, and preserves the original material.
Key concepts
- Precondition: minimum required data.
- Post-condition: required content.
- Invariant: something that can’t change.
- Predicted failure: a useful response without making things up.
What it is
The six steps are the author’s practical proposal: start from the result, define the task, calibrate freedom, verify, compare configurations, and incorporate feedback. “Better than 99%” is the promotional title of the reference, not a measured result in this course.
Why learn
The video shows different outputs across models in a visual task. This is a useful case study, but it doesn’t establish a universal ranking. Observed times from that one run also don’t guarantee duration, price, or quality for your account.
Key concepts
- A report is not the same as a benchmark.
- Repeatability requires multiple cases.
- Tools depend on real access.
- Self-evaluation requires evidence.
What it is
You’ll work with synthetic data and local files. Download the kit from the homepage, open the folder in Codex, and keep input, output, and evidence separate. The exercise doesn’t require a paid API or a connected CRM account.
Why learn
Separating folders makes it possible to redo an execution without replacing the original. With each change, you can compare the previous report with the new one and verify whether the fix had any unintended effect.
Key concepts
- dados/: immutable inputs.
- saidas/: execution results.
- evidencias/: tests and observations.
- SKILL.md: versionable procedure.