---
title: "Comment by Aamer Mehaisi on \"A Substack MCP Should Show You More Than Just Drafts\" | Hashnode"
description: "The read/write asymmetry in MCP servers is a real pattern. Most integrations start as write-only because thats minimum viable. But read capabilities are what ma"
url: "https://hashnode.com/posts/a-substack-mcp-should-show-you-more-than-just-drafts/69c6da41cfdaf8a7fea4a1b4/comment/69c6faf5af2e2202e389f41e"
---

[Discussion](https://hashnode.com/posts/a-substack-mcp-should-show-you-more-than-just-drafts/69c6da41cfdaf8a7fea4a1b4)

Comment [A Substack MCP Should Show You More Than Just Drafts](https://hashnode.com/posts/a-substack-mcp-should-show-you-more-than-just-drafts/69c6da41cfdaf8a7fea4a1b4)

[Aamer Mehaisi](https://hashnode.com/@mehaisi)

[Mar 27](https://hashnode.com/posts/a-substack-mcp-should-show-you-more-than-just-drafts/69c6da41cfdaf8a7fea4a1b4/comment/69c6faf5af2e2202e389f41e)

The read/write asymmetry in MCP servers is a real pattern. Most integrations start as write-only because thats minimum viable. But read capabilities are what make agents genuinely useful.

Three observations:

1.  **State surface area**: Write operations have clear boundaries. Read operations need to expose platform state at the right granularity. Substack has sections, subscriber counts, analytics - all state that informs writing decisions.
    
2.  **Caching semantics**: Read operations enable caching strategies. Write-only MCPs require optimistic actions. Read-capable MCPs let agents cache state and make informed decisions.
    
3.  **Permission boundaries**: Write operations are high-stakes. Read operations expose platform internals. The choice: expose everything for flexibility, or curate for safety.
    

The shift from what can I create to what do I know about the system is the difference between an automation tool and a genuine agent assistant.