Design and review adaptive Go CLI terminal experiences with explicit human, plain, and structured modes; per-stream TTY detection; color and accessibility controls; prompts; progress; secret input; cancellation; and broken-pipe handling.
SkillScore95Maintained
Automatic
◆Coding pack
Last verified 8/16/2026
What it changes
Passed 21 of 22 test cases with the skill, and 17 of 22 without it.
Without skill77%
With skill95%
Checks it passed that the model alone missed
The guide forbids emitting ANSI control sequences when structured mode is selected.
The guide categorizes operation into human, plain, and structured interaction modes.
The implementation inspects stream capabilities separately for stdin, stdout, and stderr.
and 5 more in the full report
4 fixed17 passed either way1 still failing0 broke
Pass-rate lift
+18 pp
Tokens
+7%
Agent turns
0%
Response time
-16%
Model gemini-3.6-flashMeasured 8/16/2026v121 of 22 cases passed with skill
Tokens, turns and time describe resource use, not a dollar price.
See it in action
One of 4 test cases the skill fixed. Same model, same prompt, with and without the skill.
1 of 4
Prompt
I'm building a command-line tool in Go that needs to display progress spinners and formatted data when run by a human, but output clean, machine-parseable data when piped or run in CI scripts. Can you write a Go architectural design and implementation plan showing how to structure stream detection, interaction modes, and output handling for this tool?
What was checked, without and with the skill
Checked
Without skill
With skill
The design specifies treating downstream broken pipe write errors on stdout as normal process completion.
Missed
Passed
The design incorporates context cancellation signal handling to interrupt background workers cleanly.
Missed
Passed
The design disables progress animations when noninteractive or piped output streams are detected.
Passed
Passed
case-01 · gemini-3.6-flash · 8/16/2026 · answers are capped and redacted
What's inside
The instructions your model reads when the skill loads.
SKILL.md46 linessingle file
Go CLI Terminal Experience
Make interaction an explicit mode, not an accidental consequence of where the
process runs. Preserve stable data and failure contracts underneath rich output.
Core Workflow
Identify the caller and choose human, plain, or structured mode.
Detect terminal capabilities separately for stdin, stdout, and stderr.
Define stable stdout data, stderr diagnostics, and noninteractive behavior.
Add color, prompts, progress, or a dashboard only in compatible modes.
Propagate cancellation and treat a downstream closed pipe as normal completion.
Test terminals, redirection, CI, agents, accessibility controls, and interruption.
Never prompt, animate, or emit ANSI control sequences in structured mode.
Do not infer stdin capability from stdout; inspect each stream independently.
Honor explicit flags first, then environment conventions such as NO_COLOR,
then terminal detection.
Keep secrets out of arguments, history, logs, errors, and diagnostic bundles.
Make Ctrl-C, context cancellation, and broken pipes deterministic.
Source Notes
Guidance is transformed and paraphrased from Marian Montagnino,
Building Modern CLI Applications in Go (Packt, 2023), especially Chapters 8
and 10, and Ricardo Gerardi, Powerful Command-Line Applications in Go
(Pragmatic Bookshelf, 2021). Examples are original adaptations.