MCP What are Security and Trust & Safety principles in specification?

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 

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

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

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

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:

Build robust consent and authorization flows into their applications

Provide clear documentation of security implications

Implement appropriate access controls and data protections

Follow security best practices in their integrations

Consider privacy implications in their feature designs