clarify reasoning for no origin on manual log creation and clarify automatically emitted logs origin

Author: alexsohn1126

develop-docs/sdk/telemetry/logs.mdx

@@ -309,13 +309,13 @@ If a log is generated by an SDK integration, the SDK should also set the `sentry
 
 Logs can be generated in three ways:
 
-1. User calls Sentry’s Logging API directly: No `sentry.origin`.
+1. User calls Sentry’s Logging API directly: No `sentry.origin`. Users are charged by how many bytes are used, therefore we want to minimize the size of each log.
 
 2. Captured from a logging library: Use `auto.log.<name>` format. where `<name>` is the relevant integration. For example, the .NET Serilog library emits:
   ```json
   { "sentry.origin": "auto.log.serilog" }
   ```
-3. Auto-emitted logs from other instrumented systems: Use the matching trace origin category (e.g. db, http, etc.).
+3. Auto-emitted logs from other instrumented systems: Use the `auto.<category>.<integration-name>` format as outlined in [Trace Origin](/sdk/telemetry/traces/trace-origin/) documentation.
   ```json
   { "sentry.origin": "auto.db.prisma" }
   ```