diff --git a/AGENTS.md b/AGENTS.md
index 21f6ccb..059080e 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -104,10 +104,18 @@ npm run preview
 - Prefer precise, minimal changes.
 - Do not flatter or over-explain.
 - Explain risks directly.
-- Prefer single quotes for strings unless interpolation or escaping makes double quotes better.
+- Prefer single quotes for strings unless interpolation or escaping makes
+  double quotes better.
 - Ruby: never put a space before method-call parentheses.
+- Ruby: never put a line break immediately before `)`.
 - Ruby: do not use `%w` or `%i`.
-- TypeScript and Python: use GNU-style spacing before parentheses where syntactically valid.
+- Ruby hashes are not blocks; keep `}` on the same line as the final pair.
+- Ruby hashes keep the first pair on the same line as `{` unless line length
+  requires a break.
+- Ruby blocks use separate `{ ... }` rules from hashes, with 2-space body
+  indentation.
+- TypeScript and Python: use GNU-style spacing before parentheses where
+  syntactically valid.
 - Never write Ruby, TypeScript, or TSX lines longer than 99 characters.
 - Aim to keep Ruby, TypeScript, and TSX lines within 79 characters where practical.
 - TypeScript and TSX use 4-space logical indentation.
@@ -128,6 +136,8 @@ npm run preview
 - Be careful with version tables, `version_no`, optimistic concurrency,
   wiki revisions, and restore/diff behavior.
 - Be careful with tag names, tag normalization, implications, similarities, and discard behavior.
+- Be sensitive to N+1 queries; avoid introducing them and proactively fix
+  existing N+1 issues in the code path being edited.
 - Keep migration files and `backend/db/schema.rb` consistent when changing schema.
 
 ## Frontend rules
diff --git a/backend/AGENTS.md b/backend/AGENTS.md
index 773b8ee..622272b 100644
--- a/backend/AGENTS.md
+++ b/backend/AGENTS.md
@@ -68,15 +68,22 @@ service, representation, and spec.
 - Prefer precise, minimal changes.
 - Use single quotes unless interpolation or escaping makes double quotes better.
 - Do not put a space before Ruby method-call parentheses.
+- Never put a line break immediately before `)` in Ruby.
 - Do not use `%w` or `%i` in new Ruby code.
 - Never write a Ruby line longer than 99 characters.
 - Aim to keep Ruby lines within 79 characters where practical.
 - For small Ruby method definitions that take keyword arguments, match the
   local no-parentheses style when nearby code uses it.
-- For multi-line Ruby hashes and keyword constructors, prefer a readable
-  vertical shape with the opening brace on its own line.
-- Put one logical field per line when the expression would otherwise
-  become dense.
+- Treat Ruby hash `{ ... }` style and Ruby block `{ ... }` style as separate
+  rules.
+- Do not format Ruby hashes like Ruby blocks.
+- For Ruby hashes, keep the closing `}` on the same line as the final pair.
+- Keep the first pair on the same line as `{` by default.
+- If the hash would exceed the line limit, break after `{` and indent pairs
+  by 4 spaces.
+- Put one logical pair per line when the expression would otherwise become
+  dense.
+- For Ruby blocks, use 2-space indentation for the block body.
 - Keep comments short and useful; avoid narrating obvious code.
 - Do not add production dependencies without approval.
 
@@ -186,6 +193,9 @@ service, representation, and spec.
 
 - When a controller action serializes nested associations, preload the
   associations it will touch instead of allowing N+1 queries.
+- Be sensitive to N+1 queries in all backend work.
+- Avoid introducing N+1 queries, and proactively fix existing N+1 issues when
+  you find them in the code path you are editing.
 - When an association may already be preloaded, prefer loaded-association
   checks that reuse the preloaded data without losing the efficient database
   path.