diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
index f4b45cbb8..33be05c38 100644
--- a/.github/copilot-instructions.md
+++ b/.github/copilot-instructions.md
@@ -180,6 +180,8 @@ Follow the [Stimulus Handbook](https://stimulus.hotwired.dev/handbook/introducti
 - **On every push**, update the PR title and content to reflect the current diff — preserve any existing images/screenshots in the description
 - **On every push**, update AI instruction files if the diff adds, removes, or renames anything tracked in AGENTS.md — specifically: Stimulus controllers, services, model/controller concerns, mailers, rake tasks, and directory file counts
 - **On every push**, add PR review comments on notable lines of code — decisions, trade-offs, non-obvious logic, or anything a reviewer should understand. Use `gh api` to post line comments on the diff
+- **Attribute every AI-authored GitHub comment** — `gh` posts as the authenticated user, so any comment you create (PR review comments, issue/PR comments, replies) MUST be prefixed to identify the AI agent that wrote it. Begin the comment body with `🤖 _From <agent>:_` (e.g. `🤖 _From Claude:_` or `🤖 _From Copilot:_`) followed by the content
+- **Keep GitHub comments short and to the point** — one or two sentences, stating the key insight directly. Skip preamble, restating the code, and hedging; if a comment needs more than a few lines, it usually belongs in the PR description instead
 
 ## Testing
 
diff --git a/CLAUDE.md b/CLAUDE.md
index 72ce29619..cff19b2c1 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -180,6 +180,8 @@ Follow the [Stimulus Handbook](https://stimulus.hotwired.dev/handbook/introducti
 - **On every push**, update the PR title and content to reflect the current diff — preserve any existing images/screenshots in the description
 - **On every push**, update AI instruction files if the diff adds, removes, or renames anything tracked in AGENTS.md — specifically: Stimulus controllers, services, model/controller concerns, mailers, rake tasks, and directory file counts
 - **On every push**, add PR review comments on notable lines of code — decisions, trade-offs, non-obvious logic, or anything a reviewer should understand. Use `gh api` to post line comments on the diff
+- **Attribute every AI-authored GitHub comment** — `gh` posts as the authenticated user, so any comment you create (PR review comments, issue/PR comments, replies) MUST be prefixed to identify the AI agent that wrote it. Begin the comment body with `🤖 _From <agent>:_` (e.g. `🤖 _From Claude:_` or `🤖 _From Copilot:_`) followed by the content
+- **Keep GitHub comments short and to the point** — one or two sentences, stating the key insight directly. Skip preamble, restating the code, and hedging; if a comment needs more than a few lines, it usually belongs in the PR description instead
 
 ## Ruby Version Manager