Update server features index

Author: jspahrsummers

docs/specification/server/_index.md

@@ -9,7 +9,7 @@ weight: 3
 **Protocol Revision**: {{< param protocolRevision >}}
 {{< /callout >}}
 
-Context primitives are the fundamental building blocks for providing context to language models via MCP. These primitives enable rich interactions between clients, servers, and language models. The key primitives are:
+Servers provide the fundamental building blocks for adding context to language models via MCP. These primitives enable rich interactions between clients, servers, and language models:
 
 - **Prompts**: Pre-defined templates or instructions that guide language model interactions
 - **Resources**: Structured data or content that provides additional context to the model