---
id: M05-L05
title: "Challenge: build the constraints skill"
module: M05
chapters: "10–11"
checkpoint: CP04
---

# M05-L05 — Challenge: build the constraints skill

Deliver a reusable constraints procedure with evidence that its boundaries work. This module challenge combines project guidance, skill packaging, exact-source reading, and fresh-session evaluation. Use CP04 in a new exercise folder; preserve your earlier working version.

Review the skill's purpose and input contract before changing it. It should derive constraints for an identified board or component from primary material. It should neither perform unrelated firmware edits nor invent information that the source lacks. Keep global project expectations in AGENTS.md and detailed hardware facts in the hardware reference.

Improve one demonstrated weakness from M05-L04. A weak trigger needs a more precise description. An unsupported table row needs a clearer evidence-review step and a missing-data example. A broken reference needs a corrected path. Do not redesign everything at once, because that makes it hard to explain why behavior changed.

Run the relevant request using product 5477 and BME280 sources, first explicitly if discovery needs diagnosis, then implicitly. Follow it with unrelated and incomplete-input cases in fresh tasks. Record the actual host, skill version, prompt, source scope, selection evidence, output, and verdict. The negative case must not mention the skill.

Inspect the final constraints table independently. Every factual value needs a source location. Units and conditions must survive extraction. Board-level and chip-level claims need clear identities. Inferences should be labeled, and unknowns should explain what evidence is missing and what decision remains affected.

Prepare a short handoff: where the skill lives, how to invoke it in the tested host, which cases passed or remain open, and what should be rerun after a relevant tool or source change. Do not describe a format lint as a behavior test. Do not describe document extraction as physical validation.

The challenge passes with a usable package and an evidence-backed evaluation, not merely a large folder. The five-question module quiz checks the concepts behind that work. Aim for four correct answers, retry after reading explanations, and keep practical artifacts separate from quiz progress. Chapter 16 later applies this pattern to firmware review.

## Resources and completion

Use the Sensor Monitor `CP04` download and its `README.md`; project paths in this lesson are relative to that root. Read Chapter 10–11 for the full lab and explanatory review answers. Figure IDs: SS11-02, SS11-03, SS11-05, D10. Primary references: [OpenAI AGENTS.md](https://learn.chatgpt.com/docs/agent-configuration/agents-md) and [OpenAI build skills](https://learn.chatgpt.com/docs/build-skills). Complete the [exercise](exercise.md), preserve actual evidence, and use the separate instructor answer key for self-check after attempting the task. Narration scripts are production sources; final transcripts must match the actual narrated edit.

For the incomplete case, reuse [M05-L04’s refined different-board scenario](../l04/exercise.md). Keep that course scenario distinct from the shorter request in candidate05; changing the prompt and the skill together would confound the comparison.