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Learn by example. This page provides complete skill walkthroughs you can follow to create useful skills for your agents. Each example includes the full SKILL.md file, an explanation of how it works, and how to test it.

Built-in skill walkthrough: log-troubleshooting

Comis ships with seven prompt skills in the repo’s /skills/ directory, and the easiest way to understand the format is to read a real one. Here is the manifest and body of log-troubleshooting, the skill agents reach for when the user asks “what went wrong?” or “why is the daemon slow?” Live at: <repo>/skills/log-troubleshooting/SKILL.md
What this teaches you about SKILL.md authoring:
  • Two required fields, that is it. name and description — the rest is optional. Notice there is no allowed-tools, no permissions, no inputSchema. Most real-world skills are this lean.
  • The description does the heavy lifting. Look at the trigger phrases packed into it (“logs”, “errors”, “warnings”, “what happened”, “investigating any kind of platform issue”). Comis uses this string to match the user’s intent to the right skill — a vague description like “log helper” would never get selected. Spend time on this field.
  • comis.requires.bins (under metadata.comis) is how the skill says “I need python3 on PATH”. At load time the runtime eligibility system checks this; if Python is missing, the skill is skipped with a warning rather than silently failing.
  • The body is just Markdown. No special syntax beyond standard {template} / $1 placeholders. The skill bundles a Python script next to the manifest in scripts/log-digest.py, and the body teaches the agent to call it.
Test it (after rebuilding):
The agent automatically loads log-troubleshooting, runs python3 scripts/log-digest.py ~/.comis/logs/daemon.log, and reports the top errors, slowest operations, and warnings.
Read the rest in <repo>/skills/log-troubleshooting/SKILL.md. The other six shipped skills (chart-visualization, deep-research, find-skills, image-generation, podcast-generation, video-generation) follow the same structure — skim them when picking a template for your own.

Customer support persona

A prompt skill that teaches the agent to respond as a customer support representative with specific tone, escalation rules, and response templates. Create the file at: ~/.comis/skills/customer-support/SKILL.md
How it works:
  • The allowed-tools restriction ensures the agent only uses messaging and memory tools while this skill is active — it cannot run shell commands, browse the web, or access other tools
  • The userInvocable: true setting (the default, carried under metadata.comis) means anyone in the chat can activate it with /skill:customer-support
  • The agent follows the tone, escalation, and response format rules for every reply
Test it:
Then send a message like: “I ordered a product last week and it still has not arrived.”

Daily briefing

A prompt skill that generates a morning briefing when triggered by a scheduled cron job. This example shows how skills and scheduling work together. Create the file at: ~/.comis/skills/daily-briefing/SKILL.md
How it works:
  • The argumentHint (under metadata.comis) shows users that the skill expects a timezone argument
  • The {timezone} placeholder gets replaced with whatever the user provides
  • The disableModelInvocation: false setting (the default, under metadata.comis) means the agent can also decide to use this skill on its own when relevant
Test it manually:
Automate it with scheduling: To run this automatically every morning, use the cron tool to create a scheduled job:
This tells the agent to invoke the daily briefing skill every day at 9:00 AM Eastern.

Code review checklist

A prompt skill with tool restrictions that provides a structured code review checklist. This example demonstrates how to combine instructions with specific tool access. Create the file at: ~/.comis/skills/code-review/SKILL.md
How it works:
  • The $1 placeholder is replaced with the file path the user provides
  • The allowed-tools restriction limits the agent to read-only file tools — it cannot modify files, run commands, or access the network during the review
  • The comis.requires.bins field (under metadata.comis) ensures git is installed on the system before the skill is loaded. If git is missing, the skill is marked as ineligible.
Test it:
The agent reads the file, checks each item on the checklist, and reports its findings.

Data formatter

A skill that formats CSV data into a readable Markdown table. This example shows how permissions control file access. Create the file at: ~/.comis/skills/csv-formatter/SKILL.md
How it works:
  • The permissions.fsRead field (under metadata.comis) grants the skill read access to CSV files in the ./data/ directory — and only that directory
  • The skill cannot read files outside of ./data/*.csv, write any files, or access the network
  • The argumentHint shows users what input to provide
Test it:
The agent reads the CSV file, parses the contents, and returns a neatly formatted Markdown table.

Tips for writing good skills

These tips apply to all prompt skills:
  1. Keep instructions specific and actionable. Instead of “be helpful”, write “respond with a numbered list of 3 options, each with a one-sentence explanation”.
  2. Use numbered steps for procedures. The agent follows numbered steps more reliably than unstructured paragraphs.
  3. Restrict tools to only what the skill needs. Use allowed-tools to follow the principle of least privilege. A research skill should not have access to file editing tools.
  4. Test with simple inputs first. Start with the most basic invocation and work up to complex cases. Check that template variables resolve correctly.
  5. Use argumentHint to guide users. Set it under metadata.comis to show users what inputs your skill expects so they do not have to guess — for example, an argumentHint of "[language] [file-path]".
  6. Write clear descriptions. The agent uses the description field to decide when to apply skills automatically. A vague description like “helper skill” gives the agent little to work with.
Skills are the primary way to customize your agent’s behavior. Start with one or two simple prompt skills, and expand as you learn what works best for your team.

Prompt Skills

Learn to create prompt skills

Manifest Reference

All manifest fields

Tool Policy

Control tool access