docs(tracer): update wording that it auto-disables on non-Lambda env

Author: heitorlessa

docs/core/tracer.md

@@ -10,8 +10,7 @@ Tracer is an opinionated thin wrapper for [AWS X-Ray Python SDK](https://github.
 ## Key features
 
 * Auto capture cold start as annotation, and responses or full exceptions as metadata
-* Run functions locally with SAM CLI without code change to disable tracing
-* Explicitly disable tracing via env var `POWERTOOLS_TRACE_DISABLED="true"`
+* Auto-disable when not running in AWS Lambda environment
 * Support tracing async methods, generators, and context managers
 * Auto patch supported modules by AWS X-Ray
 
@@ -357,11 +356,7 @@ Tracer keeps a copy of its configuration after the first initialization. This is
 
 ## Testing your code
 
-You can safely disable Tracer when unit testing your code using `POWERTOOLS_TRACE_DISABLED` environment variable.
-
-```bash
-POWERTOOLS_TRACE_DISABLED=1 python -m pytest
-```
+Tracer is disabled by default when not running in the AWS Lambda environment - This means no code changes or environment variables to be set.
 
 ## Tips
 

docs/index.md

@@ -223,7 +223,7 @@ aws serverlessrepo list-application-versions \
 | ------------------------------------------------- | --------------------------------------------------------------------------------- | --------------------------------------------------------------------------------- | ------------------------------------------------- |
 | **POWERTOOLS_SERVICE_NAME** | Sets service name used for tracing namespace, metrics dimension and structured logging | All | `"service_undefined"` |
 | **POWERTOOLS_METRICS_NAMESPACE** | Sets namespace used for metrics | [Metrics](./core/metrics) | `None` |
-| **POWERTOOLS_TRACE_DISABLED** | Disables tracing | [Tracing](./core/tracer) | `false` |
+| **POWERTOOLS_TRACE_DISABLED** | Explicitly disables tracing | [Tracing](./core/tracer) | `false` |
 | **POWERTOOLS_TRACER_CAPTURE_RESPONSE** | Captures Lambda or method return as metadata. | [Tracing](./core/tracer) | `true` |
 | **POWERTOOLS_TRACER_CAPTURE_ERROR** | Captures Lambda or method exception as metadata. | [Tracing](./core/tracer) | `true` |
 | **POWERTOOLS_TRACE_MIDDLEWARES** | Creates sub-segment for each custom middleware | [Middleware factory](./utilities/middleware_factory) | `false` |