diff --git a/.github/workflows/jepsen.yml b/.github/workflows/jepsen.yml
index c6d5fdd9f..793491118 100644
--- a/.github/workflows/jepsen.yml
+++ b/.github/workflows/jepsen.yml
@@ -8,28 +8,30 @@ on:
         required: true
         default: 'cas-register'
       nemesis:
-        description: 'Nemesis to use; e.g. clocks'
+        description: 'Nemesis to use: (none | clocks | single-partitions | half-partitions | ring-partitions | split-dup-validators | peekaboo-dup-validators | changing-validators | crash | truncate-tendermint | truncate-merkleeyes)'
         required: true
         default: 'none'
       dupValidators:
         description: 'Whether to have multiple validators share the same key.'
         required: false
+        default: 'false'
       superByzantineValidators:
         description: 'Should byzantine validators have just shy of 2/3 the voting weight?'
         required: false
+        default: 'false'
       concurrency:
-        description: 'How many concurrent processes to run'
+        description: 'How many workers should we run? Must be an integer and >= 10, optionally followed by n (e.g. 3n) to multiply by the number of nodes.'
         required: true
         default: 10
       timeLimit:
-        description: 'Time limit'
+        description: 'Excluding setup and teardown, how long should a test run for, in seconds?'
         required: false
       tendermintUrl:
-        description: 'Where to grab the Tendermint binary (linux/amd64)?'
+        description: 'Where to grab the Tendermint binary (linux/amd64 tarball)?'
         required: true
         default: 'https://github.com/melekes/katas/releases/download/0.2.0/tendermint.tar.gz'
       merkleeyesUrl:
-        description: 'Where to grab the Merkleeyes binary (linux/amd64)?'
+        description: 'Where to grab the Merkleeyes binary (linux/amd64 tarball)?'
         required: true
         default: 'https://github.com/melekes/katas/releases/download/0.2.0/merkleeyes_0.1.7.tar.gz'
 
@@ -46,4 +48,5 @@ jobs:
         run: ./bin/up --daemon
 
       - name: Run the test
-        run: docker exec -i jepsen-control 'cd tendermint && lein run test --nemesis ${{ github.event.inputs.nemesis }} --workload ${{ github.event.inputs.workload }}'
+        working-directory: tendermint
+        run: docker exec -i jepsen-control 'lein run test --nemesis ${{ github.event.inputs.nemesis }} --workload ${{ github.event.inputs.workload }} --concurrency ${{ github.event.inputs.concurrency }} --tendermint-url ${{ github.event.inputs.tendermintUrl }} --merkleeyes-url ${{ github.event.inputs.merkleeyesUrl }}'