CLI compatibility: agent/tools frontmatter in command files generates warnings in Copilot CLI

[bryansrevision]

Problem

When using the Copilot CLI (v1.0.2+), command files under .copilot/installed-plugins/awesome-copilot/ generate warnings on startup because they contain frontmatter fields that the CLI parser does not recognise.

Warning output

.copilot/installed-plugins/awesome-copilot/awesome-copilot/commands/suggest-awesome-github-copilot-collections.md: unknown fields ignored: agent, tools
.copilot/installed-plugins/awesome-copilot/awesome-copilot/commands/suggest-awesome-github-copilot-prompts.md: unknown fields ignored: agent, tools
.copilot/installed-plugins/awesome-copilot/devops-oncall/commands/azure-resource-health-diagnose.md: unknown field ignored: agent
.copilot/installed-plugins/awesome-copilot/devops-oncall/commands/multi-stage-dockerfile.md: unknown fields ignored: agent, tools
.copilot/installed-plugins/awesome-copilot/security-best-practices/commands/ai-prompt-engineering-safety-review.md: unknown field ignored: agent
.copilot/installed-plugins/awesome-copilot/project-planning/commands/breakdown-epic-arch.md: unknown field ignored: agent
.copilot/installed-plugins/awesome-copilot/project-planning/commands/breakdown-epic-pm.md: unknown field ignored: agent
.copilot/installed-plugins/awesome-copilot/project-planning/commands/breakdown-feature-implementation.md: unknown field ignored: agent
.copilot/installed-plugins/awesome-copilot/project-planning/commands/breakdown-feature-prd.md: unknown field ignored: agent
.copilot/installed-plugins/awesome-copilot/project-planning/commands/create-github-issues-feature-from-implementation-plan.md: unknown fields ignored: agent, tools
.copilot/installed-plugins/awesome-copilot/project-planning/commands/create-implementation-plan.md: unknown fields ignored: agent, tools
.copilot/installed-plugins/awesome-copilot/project-planning/commands/create-technical-spike.md: unknown fields ignored: agent, tools
.copilot/installed-plugins/awesome-copilot/project-planning/commands/update-implementation-plan.md: unknown fields ignored: agent, tools

Root Cause

The command files use VS Code .prompt.md frontmatter format which includes agent and tools fields:

---
mode: agent
tools: [githubRepo, codebase]
description: '...'
---

The Copilot CLI command parser only recognises name, description, and allowed-tools in command file frontmatter. The agent and tools fields are VS Code Chat-specific and are silently ignored by the CLI — but they still produce a warning per file on every CLI startup.

Impact

• 13 warning messages shown every time the Copilot CLI starts
• Noisy output that may hide legitimate warnings
• Confuses users who see warnings for files they didn't author

Suggested Fix

Option A — Dual-format guard: Strip VS Code-only fields from the YAML frontmatter before the CLI parses them, or add a format version discriminator so the CLI skips unknown fields silently (already done, but without surfacing noise).

Option B — CLI-compatible aliases: Add CLI-compatible frontmatter equivalents alongside VS Code fields where possible (e.g. map tools → allowed-tools).

Option C — Suppress known-harmless fields: Update the CLI parser to silently ignore agent and tools without generating a warning, since they are well-known VS Code fields that will never conflict.

Environment

• Copilot CLI v1.0.2
• awesome-copilot plugin installed via copilot extension install github/awesome-copilot
• Affects: awesome-copilot, devops-oncall, security-best-practices, project-planning plugin command sets

[aaronpowell]

Yes, unfortunately it's a known problem as there has been some drift in how the front matter has been implemented across CLI, VS Code, etc. and they look for different fields.

One other observation is that you seem to be using a very outdated version of the marketplace, as we don't have prompts in the repo anymore, only skills (#760 merged them together). I'd suggest that you uninstall the plugins and then remove the marketplace cache (~/.copilot/marketplace-cache), then reinstall them - that'll force a re-download of the marketplace.

I am discussing with the Copilot teams on how we can handle these warnings better though.

[heroqltetmo-boot-uber-Drive]

extracción

[heroqltetmo-boot-uber-Drive]

Option A — Dual-format guard: Strip VS Code-only fields from the YAML frontmatter before the CLI parses them, or add a format version discriminator so the CLI skips unknown fields silently (already done, but without surfacing noise).

Option B — CLI-compatible aliases: Add CLI-compatible frontmatter equivalents alongside VS Code fields where possible (e.g. map tools → allowed-tools).

Option C — Suppress known-harmless fields: Update the CLI parser to silently ignore agent and tools without generating a warning, since they are well-known VS Code fields that will never conflict.