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ColumnAI agent interface contracts, MCP, Agents SDK, ADK, and enterprise implementation7 分鐘閱讀

Define the interface contract before you buy any AI agent framework

OpenAI, Anthropic and Google ADK all point to the same operator risk: teams buy agent frameworks before deciding who approves tool calls, what evidence is kept, and where work rolls back.

Abstract audit trail map showing AI agent handoffs, approval checkpoints, and recovery paths

圖片來源: ALTOS LAB editorial visual

Key Points

  • Define what enters, what leaves, and who owns each return before selecting an agent framework.
  • Anthropic, OpenAI, and Google point to the same core: fixed processes and dynamic agent action must have clear control separation.
  • With MCP and NIST AI RMF in play, expand cautiously and document evidence and recovery paths before scaling.
  • A buying decision is valid only after your organization can prove rollback, approval, and handoff behavior in day-to-day work.

At 9:07 on Tuesday, Lina, an operations lead at a logistics company, opened four AI workspaces in one morning. Finance asked for invoice exception updates, sales needed a customer follow-up draft, and support requested priority ticket summaries. Every task landed quickly, and each screen showed green check marks.

Put simply, an agent contract is the operating sheet that says what data enters, what tool action is allowed, who reviews risky work, and where the task rolls back when evidence is weak.

Then the same hour brought a call from procurement. A discount exception had been approved, but no one could say which source record was used, which permission allowed the action, and where the result should be sent if the data looked wrong. The model had done its job fast, yet the team had no safe decision point before the change reached an external system.

This is the common state we see in enterprises that buy tools first and contracts later. The cost is not only technical errors; it is unowned decisions.

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> ALTOS LAB view: Before frameworks, define the contract: input scope, permission scope, approval scope, and rollback scope. Without these four fields, a pilot can never scale with discipline.

First define the context contract, not the model stack

The first misunderstanding is to assume an AI agent is just a faster assistant. Anthropic’s Building Effective AI Agents note is explicit: start simple, use agent-style systems only when the task truly needs dynamic steps, and separate fixed procedures from dynamic problem-solving agents. In practical terms, if the task is a fixed checklist with stable outcomes, you already have a process path. If the task needs branching, evidence gathering, and follow-up actions, you now need an agent design.

An enterprise context contract should answer four questions before any tool is attached. First, what context can enter the agent from internal systems: period, data source, freshness, and identity filters. Second, what can never enter: confidential fields, unresolved records, or external data without approval. Third, what must be tagged for every result: dataset version, source IDs, operator owner, and decision timestamp. Fourth, what to do when a request is outside policy: reject, queue for human review, or pause execution.

This is often called a simple gate, but it is the core risk engine. If context is fuzzy, every later improvement to prompts, frameworks, or models will only amplify drift.

Separate execution from approval and keep state in one place

OpenAI’s documentation highlights a useful split: Responses API suits one model turn with application-owned logic around it, while Agents SDK is for a flow where your application owns orchestration, action permissions, and state. In plain terms, orchestration means the business system decides the next step instead of letting the model act alone. For operators, this gives a practical architecture: the model suggests; your app decides. In this split, your app can keep contracts for each action and record evidence per step before moving forward.

In a human-heavy environment, do not let one permission grant become a universal permission. Build three action levels: 1) Safe action only: read-only analysis and drafting for review. 2) Conditional action: draft updates where final output waits for human confirmation. 3) Direct action: system write actions allowed only after explicit approval.

If a task involves money moves, legal commitments, or customer messages, keep it at level 2 until reliability metrics hold for repeated production cycles. OpenAI’s structure is clear here: agents should plan, work with helper modules, keep shared state, and proceed only when controls are explicit.

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Design evidence and recovery before scale

Google’s ADK announcement lays out build, interact, evaluate, and deploy. That sequence is useful because it forces teams to prove behavior before release. ADK also supports multi-agent collaboration and action modules, including MCP links, with local CLI and Web UI debugging for test cycles. It also expects evaluation beyond final text quality: final response quality and action trajectory quality.

MCP is useful as a standard connector idea, often compared to USB-C for AI apps. That metaphor is useful in one sense only: adding more connectors gives power only if your contract layer is strict. If one connector grants access to finance snapshots and another to CRM notes, the contract must state the data-sharing boundaries.

NIST AI RMF 1.0 is voluntary, but its structure is operationally strong: trustworthiness is checked across design, development, use, and evaluation. The GenAI profile published in 2024-07-26 deepens model output and synthetic content checks. The Critical Infrastructure concept note in 2026-04-07 adds pressure on continuity and impact scenarios. Treat all three as checkpoints in your contract, instead of standalone compliance paperwork.

Practical contract checklist for operators

  • ALTOS LAB checklist for this week:
  • Draft a one-page interface contract with five fields: context source, allowed tools, approval threshold, proof package, and handback target.
  • Define who can start actions and who only reviews actions.
  • Fix a maximum error budget and a daily stop rule: if two high-risk actions fail evidence checks, pause and recover manually.
  • Set evidence format now: source ID, action ID, input summary, and timestamp on every handoff.
  • Pick one pilot that can be fully reversed within 15 minutes.
  • Before buying anything, run the pilot for two weeks and record recovery paths when wrong assumptions happen.
  • Run monthly drills where a model suggestion is incorrect and still must return to a human queue.

At that point, if your team still asks why this feels heavy, answer with a simple truth: speed without recoverability is only faster damage.

ALTOS LAB judgment: If your first metric is deployment speed, you are building a demo. If your first metric is recoverability and proof quality, you are building enterprise operations.

Abstract handoff map for AI agent context, tool permissions, and approval boundaries
A safe AI agent program starts with the handoff contract, not the tool list.
Abstract workflow diagram showing evaluation loops and rollback checkpoints for AI agents
Approvals, evidence, and recovery paths must be visible before agent work scales.

Sources

  • Anthropic, Building Effective AI Agents · Anthropic · 2024/12/19

    Anthropic recommends starting with the simplest viable workflow, separating predefined workflows from dynamic agentic behavior, and adding orchestration only where it creates practical value.

  • OpenAI Agents SDK · OpenAI · 2026/06/14

    OpenAI describes the Agents SDK as a framework for orchestration, tool calls, approvals, tracing, and stateful agent applications.

  • Google Agent Development Kit documentation · Google · 2025/04/09

    Google ADK emphasizes building, interacting with, evaluating, and deploying agents, including multi-agent and tool-connected workflows.

  • Model Context Protocol introduction · Model Context Protocol · 2026/06/14

    MCP presents an open standard for connecting AI applications with data, tools, and workflows through a shared protocol.

  • NIST AI Risk Management Framework · NIST · 2024/07/26

    NIST AI RMF 1.0 frames trustworthy AI across design, development, deployment, evaluation, and ongoing risk management.