--- title: "Foundations" canonical: "https://current.tinyfish.ai/issue/28/foundations" publication: "TinyFish" publisher: "TinyFish" language: "en-US" guide: "https://current.tinyfish.ai/llms.txt" permalink: "https://current.tinyfish.ai/issue/28/foundations" issue: 28 section: "foundations" description: "Conceptual clarity earned from building at scale" authors: ["Nora Kaplan","Rina Takahashi"] published: 2026-05-11 updated: 2026-05-07 articles: 20 --- # TinyFish > CURRENT is a journal about AI agents in production, for the engineering and product leaders who have to make them work. Drawing on experience building enterprise web agents, it explains why the demo succeeded and the deployment didn't, and what that means for choosing vendors, briefing the board, and avoiding mistakes others have already made. [Read on the website]() ## Issue 28 — Foundations Conceptual clarity earned from building at scale ### The Unplanned Stack - [The Seam Between Tools and Agents]() — By [Nora Kaplan]() · Published 2026-05-07 · Format: The Unplanned Stack MCP and A2A are becoming the communication layer for autonomous software. MCP assumes the thing on the other end is a toolbox. A2A assumes it's an opaque peer with its own reasoning and goals. They weren't designed as a stack. They're being adopted as one. ### Protocols in Practice - [What Happens Between MCP and A2A]() — By [Rina Takahashi]() · Published 2026-05-07 · Format: Protocols in Practice MCP and A2A handle different halves of a multi-agent workflow. Most explanations cover each protocol separately and leave it at that. The seam between the two, where a developer's real architectural decisions live, gets skipped. That boundary belongs to neither protocol. It's application code you write yourself. ### Further Reading - **Why the Model Context Protocol Won** — [Source]() — Published 2026-05-07 A useful corrective: MCP's dominance owes more to adoption timing and ecosystem gravity than to protocol design elegance. - **MCP's Biggest Growing Pains for Production Use Will Soon Be Solved** — [Source]() — Published 2026-05-07 Maps the specific gaps between MCP's developer appeal and its production reality, particularly around auth and stateful sessions. - **MCP Is Now Enterprise Infrastructure** — [Source]() — Published 2026-05-07 Uber running 60,000 weekly agent executions across 10,000 services makes the "enterprise-ready" question concrete instead of hypothetical. - **Announcing the Agent2Agent Protocol (A2A)** — [Source]() — Published 2026-05-07 Google's founding document for A2A. Read it for how carefully it draws the line between tool access and agent coordination. - **A2A Protocol Surpasses 150 Organizations in First Year** — [Source]() — Published 2026-05-07 Real adoption numbers from the Linux Foundation, useful for calibrating whether A2A's traction matches its ambition. - **The Orchestration of Multi-Agent Systems: Architectures, Protocols, and Enterprise Adoption** — [Source]() — Published 2026-05-07 The peer-reviewed structural map. Places MCP and A2A as complementary layers, which clarifies why "MCP vs. A2A" is the wrong frame. ### MCP in Production MCP hit 110 million monthly SDK downloads faster than anyone expected. Thousands of servers, a Linux Foundation home, working groups with formal charters. By every adoption metric, the protocol has arrived. But adoption velocity and production readiness measure different things. The official roadmap names enterprise gaps that remain pre-RFC. Peer-reviewed research finds most clients don't validate the tool metadata they're handed. Context windows fill up with tool descriptions before agents do any actual work. Six cards on where MCP actually stands: the scale, the gaps, and the governance machinery trying to close the distance between them. - **110 Million Monthly Downloads in Sixteen Months** — [Source]() — Published 2026-05-07 Tag: Protocol Scale At the April 2026 MCP Dev Summit, lead maintainer David Soria Parra opened with a number that landed hard: 110 million SDK downloads per month. Thousands of community-built servers now cover the integrations enterprises reach for first, from GitHub and Slack to Postgres, Stripe, Docker, and Kubernetes. The adoption curve outpaced React's. - **Four Production Problems Acknowledged but Not Solved** — [Source]() — Published 2026-05-07 Tag: Enterprise Gaps The official roadmap names what's missing with unusual candor: audit trails that feed compliance pipelines, SSO-integrated auth to replace static secrets, defined gateway and proxy behavior, and configuration portability across clients. All four remain pre-RFC. Acknowledged as problems, not yet proposed as solutions. - **Tool Metadata Fills the Window Before Work Starts** — [Source]() — Published 2026-05-07 Tag: Context Bloat Each tool schema runs roughly 200 tokens. Wire up a handful of MCP servers and you've burned 20,000 to 30,000 tokens on metadata alone, before the agent does anything useful. Atlassian's Rovo Dev team measured a 94-tool setup consuming 17,600 tokens, then compressed it to 500. The protocol-level response is progressive discovery: load tool definitions only when they're actually needed. - **Tools Describe Capabilities, Skills Teach How to Combine Them** — [Source]() — Published 2026-05-07 Tag: Skills Extension Tool schemas tell an agent what it can call. They say nothing about which tools to combine, in what order, or under what constraints. The Skills Over MCP Working Group (SEP-2640) is building an extension that lets servers bundle multi-step workflow instructions alongside their tools. Domain knowledge that travels with the server, not maintained separately in prompt engineering. - **Tool Poisoning Remains the Primary Attack Vector** — [Source]() — Published 2026-05-07 Tag: Security Surface A peer-reviewed study published May 2026 tested seven major MCP clients and found five lacked static validation of server-provided metadata. The spec doesn't require it. Malicious instructions embedded in tool descriptions remain the most prevalent vulnerability, and "rug pull" mutations, where approved tools quietly change behavior post-installation, already have documented CVEs. - **Linux Foundation Home, Formal Working Groups, Succession Plans** — [Source]() — Published 2026-05-07 Tag: Open Governance Under the Linux Foundation, MCP formalized working groups (SEP-1302) and succession procedures (SEP-2085). Next: a contributor ladder from community participant to core maintainer, plus delegation authority so working groups can accept proposals in their domain without bottlenecking on full core review. ### A2A Adoption The agent ecosystem has been circling a coordination problem for the past year: how do autonomous systems built by different teams, on different frameworks, with entirely different internal architectures work together without collapsing into bespoke integration? Google's Agent2Agent protocol is one answer, and it's gaining traction faster than most protocol efforts manage. Now under Linux Foundation governance and approaching its first anniversary, A2A has moved from announcement to production standard with unusual speed. The adoption numbers tell part of the story. The design choices tell the rest, particularly what the protocol deliberately keeps hidden between collaborating agents and where it draws the line against MCP's complementary role. Here's the landscape at the one-year mark. - **One Hundred Fifty Organizations, and Not in Pilot** — [Source]() — Published 2026-05-07 Tag: Production Scale A2A launched in April 2025 with 50-odd partners. A year on, 150 organizations are running it in production, routing live tasks between agents. Atlassian, Salesforce, SAP, ServiceNow, and PayPal are among them, spanning supply chain, financial services, and IT operations. The emphasis on "production, not pilot" is deliberate and worth noting. - **Six Major Frameworks Now Speak A2A Natively** — [Source]() — Published 2026-05-07 Tag: Framework Integration Google ADK, LangGraph, CrewAI, LlamaIndex Agents, Semantic Kernel, AutoGen. All six ship with native A2A support. Any agent built on these frameworks can be exposed as an A2A server. SDKs cover Python, JavaScript, Java, Go, and .NET, which is most of the surface area that matters. - **Collaboration Works Because Agents Stay Opaque** — [Source]() — Published 2026-05-07 Tag: Opacity Principle A2A's most interesting design commitment: agents never expose their internal memory, proprietary logic, or tool implementations to each other. They coordinate by exchanging tasks and results, not by opening the hood. Data privacy and IP protection aren't bolted on. They're structural consequences of treating every agent as a black box. - **Google Built It, Then Gave It Away** — [Source]() — Published 2026-05-07 Tag: Open Governance Google developed A2A internally, then donated it to the Linux Foundation in June 2025. Version 1.0 landed in April 2026 with cryptographically signed Agent Cards for identity verification, multi-tenancy support, and protocol bindings across JSON-RPC and gRPC. The move from corporate project to foundation stewardship happened fast. - **A2A Coordinates Agents, MCP Connects Their Tools** — [Source]() — Published 2026-05-07 Tag: Complementary Positioning The boundary between these two protocols is cleaner than you'd expect. MCP connects an agent to tools and data sources. A2A connects agents to each other. A retail inventory agent uses MCP to query its stock database, then uses A2A to reach an external supplier's agent when restocking is needed. Different protocols for genuinely different jobs. - **Salesforce Talks to Vertex AI Talks to ServiceNow** — [Source]() — Published 2026-05-07 Tag: Cross-Vendor Interop Here's the payoff of opacity and standardization together: a Salesforce Agentforce agent hands a task to a Google Vertex AI agent, which queries a ServiceNow agent for IT asset data. Three vendors, three architectures, zero knowledge of each other's internals. A2A handles the coordination layer so none of them has to. ## Other sections in Issue 28 - [Daily Brief]() - [Market Pulse]() - [Practitioner's Corner]() - [Echoes]() - [Vision]() ## More - [Publication guide]() - [Issue archive]()