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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 allowedTools, 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 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:
  • allowedTools records the intended restriction for invocation-capable consumers. Enforce the same restriction in the agent’s tool policy; the manifest field alone is not an OS sandbox.
  • The userInvocable: true setting is retained as registry metadata. The current daemon does not route /skill:name messages directly.
  • The agent follows the tone, escalation, and response format rules for every reply
Test it: Send an ordinary-language message such as: “Use the customer-support skill. I ordered a product last week and it still has not arrived.” Verify selection in the execution trace when deterministic confirmation matters.

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 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) means the agent can also decide to use this skill on its own when relevant
Test it manually: Ask: “Use the daily-briefing skill for US/Eastern.” Automate it with scheduling: To run this automatically every morning, use the cron tool to create a scheduled job:
This asks the model to select the daily briefing skill on the schedule. Selection is model-driven, so inspect traces before relying on it for a critical workflow.

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
  • allowedTools documents the intended read-only set. Mirror it in the agent’s tool policy before treating this workflow as read-only.
  • The comis.requires.bins field 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:
  • permissions.fsRead declares the expected CSV path for review and custom consumers; it does not enforce kernel access by itself
  • Use agent tool policy, safe-path controls, and host permissions to enforce the actual file boundary
  • 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 allowedTools 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. Show users what inputs your skill expects so they do not have to guess. For example: argumentHint: "[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