diff --git a/ls/server/src/connection/README.md b/ls/server/src/connection/README.md
index 1634e7e..ea7f00d 100644
--- a/ls/server/src/connection/README.md
+++ b/ls/server/src/connection/README.md
@@ -44,9 +44,10 @@ and retains normal function resolution.
 ## Argument documentation
 
 Signature help and call-argument hover use `SimpleCommand.arguments`. A quoted
-or multiline argument remains one syntax word. Bare documented `name=value`
-arguments select their named parameter; positional words select their ordinal
-parameter and then a documented rest parameter. This describes syntax words;
+or multiline argument remains one syntax word. Documented `name=value`
+arguments select their named parameter after shell quoting is removed from the
+static key, including `"name=value"` and `"name=$value"`; positional words select
+their ordinal parameter and then a documented rest parameter. This describes syntax words;
 runtime expansion can produce a different number of shell arguments.
 
 Within a function, argument hover recognizes direct positional parameter parts
diff --git a/ls/server/src/connection/ast/word.ts b/ls/server/src/connection/ast/word.ts
index 9370cde..d128662 100644
--- a/ls/server/src/connection/ast/word.ts
+++ b/ls/server/src/connection/ast/word.ts
@@ -1,4 +1,5 @@
 import type { WordNode } from '../../zshParser/ast';
+import { hereDocDelimiter } from '../../zshParser/lexer/delimiter';
 
 const RESERVED_COMMANDS: readonly string[] = [
   'if', 'then', 'else', 'elif', 'fi', 'for', 'select', 'foreach', 'repeat',
@@ -15,8 +16,11 @@ export function commandInsertion(name: string): string {
   return "'" + name.split("'").join(escapedQuote) + "'";
 }
 
+/** Read a named key from the static word prefix, removing shell quoting without evaluating expansions. */
 export function namedKey(word: WordNode): string | null {
-  const text = word.raw;
+  const prefix = word.parts[0];
+  if (prefix?.kind !== 'stringLiteral') return null;
+  const text = hereDocDelimiter(prefix.value).delimiter;
   let index = 0;
   while (index < text.length) {
     const char = text[index];
diff --git a/ls/server/src/diagnostics/README.md b/ls/server/src/diagnostics/README.md
index d47d5ca..f39cabd 100644
--- a/ls/server/src/diagnostics/README.md
+++ b/ls/server/src/diagnostics/README.md
@@ -56,9 +56,11 @@ shell environment was obtained successfully.
 ## Parameter contracts
 
 Required arguments come from `documentationOf(definition).parameters`. Each
-syntax word supplies one positional argument unless it has a documented bare
-`name=value` key. Position numbers, optional parameters and rest parameters are
-read directly from documentation nodes. A required `$3` needs three positional
+syntax word supplies one positional argument unless its static prefix has a
+documented `name=value` key after shell quote removal. This includes
+`name="value"`, `"name=value"` and `"name=$value"`. A key that depends on an
+expansion is not treated as a statically known name. Position numbers, optional
+parameters and rest parameters are read directly from documentation nodes. A required `$3` needs three positional
 words even if `$1` and `$2` are absent from the documentation.
 
 Quoted scalar values count as one word. Words whose expansions or global aliases
diff --git a/ls/server/test/connection/providers.test.ts b/ls/server/test/connection/providers.test.ts
index 4568bc2..04e531f 100644
--- a/ls/server/test/connection/providers.test.ts
+++ b/ls/server/test/connection/providers.test.ts
@@ -130,6 +130,10 @@ describe('signature help@AST', () => {
     ['greet ¦', 0], ['greet "hello world" ¦', 1],
     ['greet "hello\nworld" ¦', 1], ['greet a ' + String.fromCharCode(92) + '\n ¦', 1],
     ['greet one=value ¦', 0], ['greet two=val¦ue', 3],
+    ['greet "one=value" ¦', 0], ['greet "two=val¦ue"', 3],
+    ['greet "two=$val¦ue"', 3], ["greet 'two=val¦ue'", 3],
+    ['greet "two=value" one=value ¦', 0], ['greet "two=value" first ¦', 1],
+    ['greet "${key}=val¦ue"', 0], ['greet "tw${key}=val¦ue"', 0],
     ['greet "hello\nworld" ¦', 1], ['greet a ' + String.fromCharCode(92) + '\n ¦', 1],
     ['print "$(greet a ¦)"', 1], ['print x | greet ¦', 0],
     ['greet a; greet ¦', 0],
@@ -176,6 +180,12 @@ describe('argument hover@AST', () => {
       contents: { value: expect.stringContaining('first') },
     });
   });
+  test.each(['greet "two=val¦ue"', 'greet "two=$val¦ue"', "greet 'two=val¦ue'",
+    'greet "one=value" "two=val¦ue"'])('引用した名前付き引数の説明を返す: %s', source => {
+    expect(fixture(source).hover()).toMatchObject({
+      contents: { value: expect.stringContaining('option two') },
+    });
+  });
   test.each(['print "$¦1"', 'local value="$1"; print "$val¦ue"',
     'local value=${1}; print "$val¦ue"', 'local value=$1; print "${val¦ue}"'])('位置引数・そのalias: %s', body => {
     const f = fixture('# $1: local first\nowner() { ' + body + ' }\n');
diff --git a/ls/server/test/connection/server.test.ts b/ls/server/test/connection/server.test.ts
index 9a2749e..d869b6a 100644
--- a/ls/server/test/connection/server.test.ts
+++ b/ls/server/test/connection/server.test.ts
@@ -322,6 +322,38 @@ describe('server@hydration stdio', () => {
     }
   }, 15000);
 
+  test('引用した名前付き引数の診断・署名・hoverを実サーバーで返す', async () => {
+    const root = fixture();
+    const caller = pathToFileURL(path.join(root, 'caller.zsh')).href;
+    fs.writeFileSync(path.join(root, 'definition.zsh'), [
+      '# $1: first', '# $message: error message',
+      'z.t._log.failure.handle() { print "$1" "$message" }', '',
+    ].join('\n'));
+    const client = startServer();
+    const source = 'z.t._log.failure.handle "message=failed: expected [ $expect_display ] but got [ $actual_display ]" first\n';
+    const request = () => bounded(client.connection.sendRequest(DocumentDiagnosticRequest.type, {
+      textDocument: { uri: caller },
+    }));
+    try {
+      await client.initialize(root, false);
+      await client.open(caller, source);
+      expect(await request()).toMatchObject({ kind: 'full', items: [] });
+      const position = { line: 0, character: source.indexOf('expected') };
+      expect(await bounded(client.connection.sendRequest(SignatureHelpRequest.type, {
+        textDocument: { uri: caller }, position,
+      }))).toMatchObject({ activeParameter: 1, signatures: [{ activeParameter: 1 }] });
+      expect(await bounded(client.connection.sendRequest(HoverRequest.type, {
+        textDocument: { uri: caller }, position,
+      }))).toMatchObject({ contents: { value: expect.stringContaining('error message') } });
+      await client.edit(caller, 'z.t._log.failure.handle first\n', 2);
+      expect(await request()).toMatchObject({ kind: 'full', items: [{
+        code: 'missing-named-argument', message: 'Missing required named argument: message',
+      }] });
+    } finally {
+      await client.close();
+    }
+  }, 15000);
+
   test('AST診断・環境解決・抑制・依存先変更を実サーバーで反映する', async () => {
     const root = fixture();
     const definition = path.join(root, 'definition.zsh');
diff --git a/ls/server/test/diagnostics/main.test.ts b/ls/server/test/diagnostics/main.test.ts
index 6d4a763..0043d98 100644
--- a/ls/server/test/diagnostics/main.test.ts
+++ b/ls/server/test/diagnostics/main.test.ts
@@ -74,7 +74,29 @@ describe('call diagnostics@AST', () => {
     const doc = '# $option: value\ngreet() { print "$option" }\n';
     expect(semantic(fixture('greet option=""\n', doc).items)).toEqual([]);
     expect(semantic(fixture('greet option=\n', doc).items)).toEqual([]);
-    expect(semantic(fixture('greet "option=value"\n', doc).items)).toMatchObject([{ code: 'missing-named-argument' }]);
+    expect(semantic(fixture('greet "option=value"\n', doc).items)).toEqual([]);
+  });
+  test.each(['"option=value with spaces"', '"option="', '"option=$value"',
+    "'option=value with spaces'", 'op"tion"=value', '"option"="$value"',
+    'option="value"', 'op\\tion=value'])('引用を除いた静的な名前付き引数を照合する: %s', argument => {
+    const doc = '# $option: value\ngreet() { print "$option" }\n';
+    expect(semantic(fixture('greet ' + argument + '\n', doc).items)).toEqual([]);
+  });
+  test.each(['"other=value"', '"9option=value"', '"option-extra=value"', '"option"'])('引用しても不足した名前付き引数を検出する: %s', argument => {
+    const doc = '# $option: value\ngreet() { print "$option" }\n';
+    expect(semantic(fixture('greet ' + argument + '\n', doc).items))
+      .toMatchObject([{ code: 'missing-named-argument', message: 'Missing required named argument: option' }]);
+  });
+  test('引用した名前付き引数を位置引数へ数えない', () => {
+    const doc = '# $1: first\n# $option: value\ngreet() { print "$1" "$option" }\n';
+    expect(semantic(fixture('greet "option=value"\n', doc).items))
+      .toMatchObject([{ code: 'missing-positional-argument', message: 'Missing required argument(s): $1' }]);
+    expect(semantic(fixture('greet "option=$value" first\n', doc).items)).toEqual([]);
+  });
+  test('失敗ログの実例を名前付き引数として認識する', () => {
+    const doc = '# $message: error message\nz.t._log.failure.handle() { print "$message" }\n';
+    const source = 'z.t._log.failure.handle "message=failed: expected [ $expect_display ] but got [ $actual_display ]"\n';
+    expect(semantic(fixture(source, doc).items)).toEqual([]);
   });
 });