diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
index d998cc2..c720e96 100644
--- a/.github/copilot-instructions.md
+++ b/.github/copilot-instructions.md
@@ -21,6 +21,8 @@ Copilot and other AI assistants must follow these guidelines when working in thi
 - Write the PR title and description in English, regardless of the language used in the conversation.
 - Do not mention Claude, Anthropic, Copilot, or any AI assistant in the PR title or description.
 - Do not include AI session links, "Co-Authored-By" trailers for AI assistants, "Generated with ..." notices, or any other reference indicating the PR was created with AI assistance.
+- Follow the PR template in `.github/PULL_REQUEST_TEMPLATE.md`. Use its sections and do not add extra sections beyond it.
+- Do not add a "Validation", "Verification", "Testing", or similar section that lists `reihitsu-format`, `dotnet build`, `dotnet test`, or other build/test commands. Build and tests run automatically as PR checks, so restating them in the description is unnecessary.
 
 ## Build, test, and lint
 
diff --git a/AGENTS.md b/AGENTS.md
index e28a6a9..d023594 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -26,6 +26,8 @@ null handling, suppressed analyzer rules) are imported below and are
 - Write the PR title and description in English, regardless of the language used in the conversation.
 - Do not mention Codex, Anthropic, or any AI assistant in the PR title or description.
 - Do not include Codex session links, "Co-Authored-By: Codex" trailers, "Generated with Codex" notices, or any other reference indicating the PR was created with AI assistance.
+- Follow the PR template in `.github/PULL_REQUEST_TEMPLATE.md`. Use its sections and do not add extra sections beyond it.
+- Do not add a "Validation", "Verification", "Testing", or similar section that lists `reihitsu-format`, `dotnet build`, `dotnet test`, or other build/test commands. Build and tests run automatically as PR checks, so restating them in the description is unnecessary.
 
 ## Build, test, and format
 
diff --git a/CLAUDE.md b/CLAUDE.md
index 18eac1c..35f9ae0 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -26,6 +26,8 @@ null handling, suppressed analyzer rules) are imported below and are
 - Write the PR title and description in English, regardless of the language used in the conversation.
 - Do not mention Claude, Anthropic, or any AI assistant in the PR title or description.
 - Do not include Claude session links, "Co-Authored-By: Claude" trailers, "Generated with Claude" notices, or any other reference indicating the PR was created with AI assistance.
+- Follow the PR template in `.github/PULL_REQUEST_TEMPLATE.md`. Use its sections and do not add extra sections beyond it.
+- Do not add a "Validation", "Verification", "Testing", or similar section that lists `reihitsu-format`, `dotnet build`, `dotnet test`, or other build/test commands. Build and tests run automatically as PR checks, so restating them in the description is unnecessary.
 
 ## Build, test, and format