Adjusted should fail docs (#1280)

* Adjusted should fail docs

* wording changes

* minor wording change

Author: sujaya-sys

site/content/docs/api-checks/request-settings.md

@@ -25,9 +25,12 @@ An API check starts with creating an HTTP request including a HTTP verb (GET, PO
 - Available methods are `GET, POST, PUT, HEAD, DELETE, PATCH`
 - URL's are checked for correctness and must start with either `http://` or `https://`
 
-Checking the **"This request should fail"** box allows you to treat HTTP error codes (4xx and 5xx) as correct responses. This comes
-in handy when testing 404 pages or 500 error handling.
+Checking the **"This request should fail"** checkbox allows you to treat HTTP error codes (4xx and 5xx) as correct responses. This comes in handy when testing 404 pages or 500 error handling.
 
+When enabled:
+  * ✅ Failed responses (4xx, 5xx) → check passes
+  * ✅ Successful responses → check passes
+  * ❌ Failed assertions → check fails
 
 ## Body
 

site/content/docs/tcp-checks/_index.md

@@ -16,7 +16,7 @@ For example, use these checks to verify that:
 
 * Your mail server is online and responds to IMAPS requests quickly.
 * Your FTP server responds correctly to commands.
-* Your firewall blocks access to certain ports.
+* Your custom TCP-based service returns the expected response when sent a health check message.
 
 ![Screenshot of the TCP check overview page](/docs/images/tcp-checks/tcp-check-overview.png)
 
@@ -30,7 +30,7 @@ The main part of your check is the TCP request, which defines the endpoint to mo
 
 * **Target:** The TCP endpoint to monitor, as defined by a hostname or IP address (e.g. `tcpbin.com` or `192.168.1.1`) and a port (e.g. `4242`).
 * **IP family:** The default is IPv4. If needed, change the [IP family](/docs/monitoring/ip-info/#ipv4-and-ipv6-support) setting to IPv6.
-* **This request should fail:** Enable this option to mark failed connections as passed. Please note that failing assertions will still cause the check to fail.
+* **This request should fail:** Enable this option to treat connection failures (e.g. timeouts or refused ports) as passed. Please note that successful connections will continue to pass. Only failed assertions will cause the check to fail.
 * **Data to send:** The content included in the TCP request. For example, this could be text or protocol-specific commands expected by the target service.
 
 To validate the response, you can set: