Add comments on "untestable" tests directory

2 files changed, 10 insertions, 2 deletions

diff --git a/readme.md b/readme.md
index ac24658d9..6fbe60c6a 100644
--- a/readme.md
+++ b/readme.md
@@ -127,6 +127,7 @@ However, if you are short on time, you can just run the tests specific to your
 changes by only running the corresponding categories of tests. Travis CI verifies
 that all tests pass before allowing the pull request to be accepted, so only
 running specific tests should be harmless.
+Integration tests should go in ``tests/untestable``.
 
 If you're looking for ways to contribute, please look at our [issue tracker][nim-issues].
 There are always plenty of issues labelled [``Easy``][nim-issues-easy]; these should
diff --git a/tests/untestable/readme.markdown b/tests/untestable/readme.markdown
index fcb7f4f28..de1ba9459 100644
--- a/tests/untestable/readme.markdown
+++ b/tests/untestable/readme.markdown
@@ -1,2 +1,9 @@
-This directory contains tests which are not automatically executed
-for various reasons. Mainly due to dependencies on external services.
\ No newline at end of file
+This directory contains integration tests which are not automatically executed
+for various reasons:
+- dependency on external services
+- dependency on files / configuration / state of the local host
+- tests that are extremely slow or require large amounts of memory or storage
+- tests that spawn local daemons
+
+Integration tests can become stale very quickly. Automated ./koch tests are
+strongly recommended.