[RFC] Purpose Assertions and Provenance-Aware Tool Semantics

[mmethodz]

Pre-submission Checklist

• I have verified this would not be more appropriate as a feature request in a specific repository
• I have searched existing discussions to avoid duplicates

Your Idea

Hi I am Mika, developer of DreamGraph,

This is an exploratory RFC/discussion proposal based on real-world multi-agent orchestration and graph-grounded tooling experience.

MCP currently standardizes tool capability exposure well, but it does not currently provide a standard way for tools to express:

• contextual authority,
• provenance-backed relevance,
• evidence scope/freshness,
• or confidence grounded in inspectable evidence.

As a result, planners often treat all tools as capability peers even when omission of certain context-authoritative tools materially increases architectural drift risk.

This proposal explores whether MCP could support optional purpose assertions and provenance-aware tool semantics while preserving full host/model autonomy.

The intent is NOT to force tool invocation.

The intent is to standardize a way for tools to expose evidence-backed relevance claims so planners can make more informed decisions.

Draft proposal attached below for discussion and feedback.
mcp_purpose_assertions_proposal_draft.md

Scope

• Protocol Specification
• SDK Features
• Documentation
• Developer Experience
• Other

[mmethodz]

Exactly — the core issue is that most current agent stacks flatten fundamentally different authority domains into one undifferentiated prompt stream.

A retrieved document, a user instruction, a tool result, a generated argument proposal, and a system policy may all be represented as text, but they are not semantically equivalent and should not inherit the same execution authority.

My concern is that once provenance is lost, downstream components can no longer distinguish:

• “context that may inform reasoning”
• from “context authorized to mutate goals or trigger side effects.”

The RFC is trying to make those boundaries explicit and machine-visible rather than implicit prompt-engineering conventions.

I think this becomes increasingly important as agents become more multi-hop and tool-compositional.

[mmethodz]

Even when graph-grounded retrieval is available, agent systems often regress toward flat-text recency heuristics unless tool authority and provenance are continuously reasserted. In practice this can produce weaker answers than the underlying retrieval substrate could support.