diff --git a/README.md b/README.md
index 9067648..1940b6b 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,48 @@
 # stackql-assert
-Runs a unit test with a command, comparing the expected output with the actual output.
+
+The `stackql/stackql-assert` action is a JavaScript action that sets up StackQL CLI in your GitHub Actions workflow by:
+
+- Downloading a latest Stackql CLI and adding it to the `PATH`.
+- Setup AUTH env var in the Github Action
+
+This action can be run on `ubuntu-latest`, `windows-latest`, and `macos-latest` GitHub Actions runners, and will install and expose the latest version of the `stackql` CLI on the runner environment.  
+
+# Usage
+
+## AUTH
+> **Note**
+> stackql-assert action uses same auth setup as [stackql-exec](https://github.com/stackql/stackql-exec/blob/main/README.md)
+> [Learn more](https://stackql.io/docs/getting-started/authenticating) about authentication setup when running stackql
+
+### Example auth string
+```
+{   "google": { "type": "service_account",  "credentialsfilepath": "sa-key.json" },
+    "github": { "type": "basic", "credentialsenvvar": "STACKQL_GITHUB_CREDS" }}
+```
+It can be passed with `auth_str` as a string, or stored in a file and pass filename to `auth-obj-path`
+- For "basic" auth, you need to set a environment variable with same name as the value of `credentialsenvvar` in the auth string for the Github Action step. You can use [Github Secrets](https://docs.github.com/en/actions/reference/encrypted-secrets) to store the value of the environment variable, and use env to pass it to the action. For example:
+```
+env:
+  STACKQL_GITHUB_CREDS: ${{ secrets.STACKQL_GITHUB_CREDS }}
+```
+- For "service_account" auth, you need to store the credentials into a file; You can follow the example of `Prep Google Creds (bash)` step in the [example workflow](./.github/workflows/stackql-assert.yml)
+
+## Test Query
+- Use `test_query` or `test_query_path` to pass the test query to the action. The test query should be a valid StackQL query. The action will run the query and check if the result is empty or not. If the result is empty, the action will fail the step.
+- Either `test_query` or `test_query_path` is required. If both are provided, `test_query` will be used.
+- query example can be found in [example workflow](./.github/workflows/stackql-assert.yml) and [example .iql file](./.github/workflows/workflow_scripts)
+
+## Expected Result
+- Use `expected_results_str` or `expected_results_file_path` to pass the expected result to the action. The expected result should be a valid JSON object. The action will compare the result with the expected result. If the result is not the same as the expected result, the action will fail the step.
+- Either `expected_results_str` or `expected_results_file_path` is required. If both are provided, `expected_results_str` will be used.
+- Expected result example can be found in [example workflow](./.github/workflows/stackql-assert.yml) and [example .json file](./.github/workflows/workflow_scripts)
+
+
+## Input
+- `auth_obj_path` - Path to the auth object file.
+- `auth_str` - Auth string.
+- `test_query` - Test query to run (overrides test_query_path).
+- `test_query_path` - Path to the test query file.
+- `expected_rows` - Expected number of rows in the result.
+- `expected_results_str` - expected result from executing test query, support object string (overrides expected_results_file_path)
+- `expected_results_file_path` - file that stores expected result, json is support
\ No newline at end of file
diff --git a/action.yml b/action.yml
index d0e3144..c7089d7 100644
--- a/action.yml
+++ b/action.yml
@@ -18,7 +18,7 @@ inputs:
     description: expected number of rows from executing test query
     required: false
   expected_results_str:
-    description: expected result from executing test query, support object string, overrides expected_results_file_path
+    description: expected result from executing test query, support json string, overrides expected_results_file_path
     required: false
   expected_results_file_path:
     description: file that stores expected result, json is support
diff --git a/action_scripts/execute.sh b/action_scripts/execute.sh
index 6faa50e..f608b47 100644
--- a/action_scripts/execute.sh
+++ b/action_scripts/execute.sh
@@ -7,8 +7,14 @@ if [ -z "$AUTH" ]; then
   exit 1
 fi
 
-if [ -z "$QUERY_FILE_PATH" ]; then
-  stackql exec "$QUERY" --auth="${AUTH}" --output="${OUTPUT}" 
+if [ -z "$QUERY" ] && [ -z "$QUERY_FILE_PATH" ]; then
+  echo "ERROR: Either QUERY or QUERY_FILE_PATH must be set."
+  exit 1
+fi
+
+if [ -z "$QUERY" ]; then
+  stackql exec -i "$QUERY_FILE_PATH" --auth="${AUTH}" --output="${OUTPUT}"
 else
-  stackql exec -i "$QUERY_FILE_PATH" --auth="${AUTH}" --output="${OUTPUT}" 
-fi
\ No newline at end of file
+  stackql exec "$QUERY" --auth="${AUTH}" --output="${OUTPUT}"
+fi
+