Add security and T&S section to spec page

Author: jspahrsummers

docs/specification/_index.md

@@ -59,6 +59,45 @@ Clients may offer the following feature to servers:
 - Error reporting
 - Logging
 
+## Security and Trust & Safety
+
+The Model Context Protocol enables powerful capabilities through arbitrary data access and code execution paths. With this power comes important security and trust considerations that all implementors must carefully address.
+
+### Key Principles
+
+1. **User Consent and Control**
+   - Users must explicitly consent to and understand all data access and operations
+   - Users must retain control over what data is shared and what actions are taken
+   - Implementors should provide clear UIs for reviewing and authorizing activities
+
+2. **Data Privacy**
+   - Hosts must obtain explicit user consent before exposing user data to servers
+   - Hosts must not transmit resource data elsewhere without user consent
+   - User data should be protected with appropriate access controls
+
+3. **Tool Safety**
+   - Tools represent arbitrary code execution and must be treated with appropriate caution
+   - Hosts must obtain explicit user consent before invoking any tool
+   - Users should understand what each tool does before authorizing its use
+
+4. **LLM Sampling Controls**
+   - Users must explicitly approve any LLM sampling requests
+   - Users should control:
+     - Whether sampling occurs at all
+     - The actual prompt that will be sent
+     - What results the server can see
+   - The protocol intentionally limits server visibility into prompts
+
+### Implementation Guidelines
+
+While MCP itself cannot enforce these security principles at the protocol level, implementors **SHOULD**:
+
+1. Build robust consent and authorization flows into their applications
+2. Provide clear documentation of security implications
+3. Implement appropriate access controls and data protections
+4. Follow security best practices in their integrations
+5. Consider privacy implications in their feature designs
+
 ## Learn More
 
 Explore the detailed specification for each protocol component: