Design commands

Skill pantheon-org/tekhne/skills/agentic-harness/opencode-toolkit/design-commands

Create custom /slash commands for repetitive tasks in OpenCode. Use when user wants to create a command, automate a workflow, make a shortcut, add a slash command, set up automation, create a /test, /review, /deploy, /commit, /fix, /build, /lint, /spellcheck, /migrate, or /ci command. Also use when writing a command file, configuring command frontmatter, using $ARGUMENTS placeholders, setting agent: plan, using subtask: true, injecting shell output with !cmd, referencing files with the at-file syntax in a command template, or choosing between a slash command, agent, and skill.From its SKILL.md

Install

npx -y skills add pantheon-org/tekhne --skill design-commands

Assembled from the repository path, not quoted from the project. Check it against their README if it does not work.

2 things to look at

9 stars9 stars. Stars are a popularity signal and not a quality one, but at this level it is likely that nobody has read this closely except its author, and you would be relying on your own review.
runs commandsInstructs the agent to run 1 command, including `bun run opencode`.

SKILL.md

3.5 KB, 732 tokens by cl100k_base, as published. Nobody here has run it

Command Creator

Quick Start

Create .opencode/commands/<name>.md:

---
description: Run tests and fix all failures automatically
---

Run the full test suite, identify any failures, and fix them.

1. Run `npm test`
2. For each failure, identify root cause and fix
3. Re-run to verify all pass

Invoke it in OpenCode: /test

Run bun run opencode to start, then type /<name> to invoke your command.

Mindset

Slash commands are user-to-agent shortcuts — markdown files with an instruction template. User types /test → OpenCode substitutes placeholders → agent executes.

Decision rule:

Human wants a shortcut → Command
Agent needs standing instructions → Skill
Task needs a persona → Agent

When to use: Repetitive multi-step tasks that need a one-word trigger. When NOT to use: Do not create a command for one-off tasks — just type the instruction directly. Do not use commands for interactive workflows; commands are one-shot. Modes: no agent: = default build (read/write); agent: plan = read-only; subtask: true = fire-and-forget.

Template Placeholders

$ARGUMENTS — all args; $1/$2 — positional; !cmd — shell output injection; @filename — include file content.

# Dynamic context injection example
!git log --oneline -5

---
description: Deploy to staging with context
agent: plan
subtask: true
---
Deploy $ARGUMENTS using the steps in docs/deploy.md.
!git log --oneline -3

Anti-Patterns

NEVER use $ARGUMENTS more than once in a command body. WHY: The placeholder is substituted literally — using it twice creates duplicate content that confuses the agent.

# BAD — duplicate content
Review $ARGUMENTS. Focus on $ARGUMENTS for security issues.

# GOOD — wrap in XML once
<target>$ARGUMENTS</target>
Review the target file for security issues and bugs.

NEVER tell the agent to "run /command" inside a command body. WHY: Agents cannot invoke slash commands from within a command — only users can type /cmd.

# BAD
After fixing, run /test to verify.

# GOOD
After fixing, run `npm test` to verify.

NEVER use agent: plan for commands that write files. WHY: The plan agent is read-only and will refuse any write operation, silently failing the command.

# BAD
---
agent: plan
---
Create a new file called output.md with the results.
# GOOD — remove agent: plan for write operations

References

references/command-patterns.md — Creation phases, example commands (/test, /review, /commit, /deploy, /spellcheck), pattern library
references/frontmatter-reference.md — Complete frontmatter fields and placeholder reference

Eval Scenarios: Scenario 0: Deploy | Scenario 1: Spellcheck | Scenario 2: Fix anti-patterns