UPDATE: This extension will cease to exist and give place to a nuget package instead.

Get it at:
https://www.nuget.org/packages/CodingGuidelines
And as always, give a helping hand at github:
https://github.com/SamirHafez/CSharpCodingGuidelines

Coding guidelines tries to follow Coding Guidelines for C# ( http://csharpguidelines.codeplex.com )

It is a beta version that includes the following Maintainability guidelines:

AV1570: Always check the result of an as operation;
AV1564: Avoid methods that take a bool flag;
AV1561: Don't allow methods and constructors with more than three parameters;
AV1545: Don't use if-else statements instead of a simple (conditional) assignment;
AV1540: Be reluctant with multiple return statements;
AV1532: Avoid nested loops;
AV1525: Don't make explicit comparisons to true or false;
AV1520: Only use var when the type is very obvious;
AV1502: Avoid conditions with double negatives;
AV1500: Methods should not exceed 7 statements.

It is still a work in progress but the good news is:

You can contribute via the github public repository ( http://github.com/SamirHafez/CSharpCodingGuidelines ).

Feel free to add guidelines, code fixes, or even test cases.