Finding questions to answer - Part 2
There are some usability issues with @QuestionTags:


The ordering of tags matters. I think in the typical use case that's not the desired behavior
The input format is hackish (the implementation too) and unintuitive


I have an alternative suggestion that has different downsides:


Use multiple tag input fields, for example @Tag1, @Tag2, and so on
The advantage is that you could enter tags in any order, and without funky input rules
The disadvantage is that the number of tags you can enter will be limited to the number of fields you provide
Note that this approach will also open the possibility to choose the condition for for matching tags: they can be AND-ed or OR-ed. Your choice, or give another input to users to let them decide


The numbered fields are not exactly pretty, but I think the query will be easier to use this way. (Can be subjective.)

You could do similarly for matching keywords in the title.

Note that I dropped "Question" from the parameter names, to simplify to @TagN. On the network only questions can have tags, so this is obvious.

Other notes:


The semicolons at the end of variable declarations are unnecessary
It would be nice to make title optional
The repeated [Posts]. prefix of fields are not necessary, and a bit of a noise


Example implementation with some of the improvements explained above:

DECLARE @MinimumQuestionVotes INT = ##MinimumQuestionVotes:int?0##
DECLARE @MaximumQuestionAnswers INT = ##MaximumQuestionAnswers:int?0##
DECLARE @Tag1 NVARCHAR(50) = RTRIM(LTRIM(##Tag1:string? ##))
DECLARE @Tag2 NVARCHAR(50) = RTRIM(LTRIM(##Tag2:string? ##))
DECLARE @Tag3 NVARCHAR(50) = RTRIM(LTRIM(##Tag3:string? ##))
DECLARE @TitleContains NVARCHAR(250) = RTRIM(LTRIM(##TitleContains:string? ##))

SELECT
    Id AS [Post Link]
  , OwnerUserId AS [User Link]
  , Score
  , Tags
  , ViewCount
  , AnswerCount
  FROM Posts WHERE
        ClosedDate IS NULL
    AND PostTypeId = 1
    AND Score &gt;= @MinimumQuestionVotes
    AND AnswerCount &lt;= @MaximumQuestionAnswers
    AND (@Tag1 = '' OR Tags LIKE '%' + @Tag1 + '%')
    AND (@Tag2 = '' OR Tags LIKE '%' + @Tag2 + '%')
    AND (@Tag3 = '' OR Tags LIKE '%' + @Tag3 + '%')
    AND (@TitleContains = '' OR Title LIKE '%' + REPLACE(@TitleContains, ' ', '%%') + '%')
  ORDER BY Score DESC;