Primitive Grouping Interest Group

⚠️ Experimental — This repository is an incubation space for the Primitive Grouping Interest Group. Contents are exploratory and do not represent official MCP specifications or recommendations.

Mission

This Interest Group explores how MCP Primitives (Tools, Resources, Prompts, Tasks) might be organized, beyond the flat lists that are maintained by the protocol, and how such organization might benefit both MCP servers and clients.

Scope

In Scope

• Requirements gathering: Documenting use cases and constraints
• Pattern exploration: Testing and evaluating various approaches
• Proof of concepts: Maintaining a shared repo of reference implementations and experimental findings

Out of Scope

• Approving spec changes: This IG does not have authority to approve protocol changes; recommendations flow through the SEP process
• Implementation mandates: We can document patterns but not require specific client or server behavior

Problem Statement

Flat lists of MCP primitives can be long and cumbersome to work with.

• Context overload — When loaded into the context of an LLM, a primitive list can overwhelm the model and lead to confusion and poor selection
• Costly operation - Long lists can consume many tokens, leading to higher costs for users.
• Poor developer experience — Lack of organizational tools for primitives makes them harder to manage and maintain

See the Problem Statement for full details.

Repository Contents

Facilitators

Lifecycle

Current Status: Active Exploration

Graduation Criteria (IG → WG)

This IG may propose becoming a Working Group if:

• Clear consensus emerges on an approach requiring sustained spec work
• Cross-cutting coordination requires formal authority delegation
• At least two Core Maintainers sponsor WG formation

Retirement Criteria

• Problem space resolved (conventions established, absorbed into other WGs)
• Insufficient participation to maintain momentum
• Community consensus that grouping doesn't belong in MCP protocol scope

Work Tracking

Success Criteria

• Short-term: Documented consensus on requirements and evaluation of existing approaches
• Medium-term: Clear recommendation (convention vs. protocol extension vs. both)
• Long-term: Interoperable grouping convention across MCP servers and clients