XML-like Tags for AI Content

A writing convention for adding XML-like labels to Markdown files that AI agents read, such as agent instructions, skills, prompts, and examples.

In plain words
What is it for?
Use it when organizing AI instructions, marking reusable output templates, separating strict rules from advice, or identifying reference material and user content.
Why use it?
It makes the intended role of each block clearer, so an agent can distinguish instructions from templates, examples, rules, and user-facing text.

Instructions file for GitHub Copilot

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add instructions/ikcode-dev/copilot-kit/ai-content-xml-tags
Clone the repo
git clone --depth 1 https://github.com/ikcode-dev/copilot-kit

Made for: GitHub Copilot.

Per session 1,961 This file is loaded in full into every session.
When invoked 1,961 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.01961 $0.01961
Opus 5 $0.00981 $0.00981
Sonnet 5 $0.00392 $0.00392
Haiku 4.5 $0.00196 $0.00196

Measured 2d ago against content hash e59710b6ca2f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

XML-like Tags for AI Content scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.github/instructions/ai-content-xml-tags.instructions.md · 207 lines

How it starts

The opening of the file, as written. The whole thing — 207 lines — stays where its author put it; the contents beside it link to each section on GitHub.

XML-like Tags for AI-Consumed Content

Markdown files in .github/agents/, .github/skills/, .github/prompts/, and .github/instructions/ are consumed primarily by AI agents, not humans. Standard Markdown conveys structure (headers, lists, tables) but not content type — the agent can't reliably distinguish "follow this instruction" from "output this template" from "learn from this example."

XML-like tags solve this by wrapping content blocks with explicit semantic boundaries. They tell the agent what kind of content a block is and how to process it.

When to Use Tags

Use XML-like tags when Markdown alone creates ambiguity about content type. Specifically:

  • Templates vs instructions — Is a code block something to fill in and output, or an example to learn from? Wrap it in <template> or <example>.
  • Hard rules vs advisory guidance — Are these bullet points non-negotiable constraints or suggestions? Wrap them in <rules> or <best-practices>.
  • Agent content vs user content — Should the agent process this internally or display it verbatim? Wrap user-facing output in <user-message>.
  • Action items vs reference material — Should the agent iterate through a checklist or read it for context? Wrap checklists in <validation> or <questions>.

Do not use tags when Markdown is unambiguous on its own — explanatory prose, section introductions, and standard tables don't need wrapping.

Tag Vocabulary

Every tag below is part of the standard vocabulary. Use these exact tag names — do not invent one-off tags.

Action Tags (agent should DO something with this content)

Tag Purpose Agent action
<questions> Interview questions to ask the user before proceeding Iterate through and ask each question
<validation> Checklist to verify before reporting completion Iterate through every item and confirm
<context-gathering> Steps for scanning workspace/environment before acting Execute each scan step in order

Read the full file on GitHub · 207 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 207 lines · 1,961 tokens per session scan A e59710b6ca2f

Subscribe to this mod's changes

XML-like Tags for AI Content is an instructions file published in the GitHub repository ikcode-dev/copilot-kit (29 stars, last pushed 5mo ago), licensed MIT. It adds 1,961 tokens to every session, about $0.0098 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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