title: Code snippet shortcut doesn't work everywhere
body: <p>I have a code snippet <code>string.Format(@"")</code> with a shortcut <code>sf</code> that inserts the snippet and places the cursor in between the two double quotes.  Really convenient.  I can normally use it, of course, by just typing <code>sf</code> and hitting tab twice:</p>
  
  <p><a href="https://i.stack.imgur.com/Avl6g.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Avl6g.png" alt="enter image description here"></a></p>
  
  <p>However, I've just discovered that the shortcut doesn't work in all locations.  For example, if I'm building this statement:</p>
  
  <pre><code>if(true) throw new FormatException() // &lt;-- cursor is inside these parens
  </code></pre>
  
  <p>and I hit <code>sf</code>, the shortcut does not appear in the intellisense menu, and if I hit <kbd>Tab</kbd> twice, it doesn't generate the snippet.  Why?</p>
  
  <p>I have tried searching for "C# code snippet shortcut sometimes doesn't work", "C# code snippet shortcut doesn't work", "visual studio code snippet sometimes doesn't work" among others, and I can't find anything useful about it.</p>
  
  <p><strong>EDIT:</strong> Here is the snippet definition:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;CodeSnippets xmlns="http://schemas.microsoft.com/VisualStudio/2005/CodeSnippet"&gt;
    &lt;CodeSnippet Format="1.0.0"&gt;
      &lt;Header&gt;
        &lt;SnippetTypes&gt;
          &lt;SnippetType&gt;Expansion&lt;/SnippetType&gt;
        &lt;/SnippetTypes&gt;
        &lt;Title&gt;String.Format with @&lt;/Title&gt;
        &lt;Author&gt;Rory&lt;/Author&gt;
        &lt;Description&gt;
        &lt;/Description&gt;
        &lt;HelpUrl&gt;
        &lt;/HelpUrl&gt;
        &lt;Shortcut&gt;sf&lt;/Shortcut&gt;
      &lt;/Header&gt;
      &lt;Snippet&gt;
        &lt;Declarations&gt;
          &lt;Literal Editable="true"&gt;
            &lt;ID&gt;anchor&lt;/ID&gt;
            &lt;ToolTip&gt;
            &lt;/ToolTip&gt;
            &lt;Default&gt;
            &lt;/Default&gt;
            &lt;Function&gt;
            &lt;/Function&gt;
          &lt;/Literal&gt;
        &lt;/Declarations&gt;
        &lt;Code Language="csharp" Delimiter="$" Kind="method body"&gt;&lt;![CDATA[string.Format(@"$selected$$end$")]]&gt;&lt;/Code&gt;
      &lt;/Snippet&gt;
    &lt;/CodeSnippet&gt;
  &lt;/CodeSnippets&gt;
  </code></pre>