/agent-builder

name: agent-builder
description: Build Anthropic Managed Agents through a non-technical conversation. The skill asks the user what kind of agent they want, which connectors and abilities it should have, and then silently translates that into Anthropic's Managed Agents REST API: creates the Agent, Environment, Vault and credentials, attaches MCP servers and Skills, opens a Session, and sends a first message. Hides the developer details. USE THIS SKILL WHEN user says "agent builder", "build an agent", "create an agent", "managed agent", "managed agents", "deploy an agent", "anthropic agent", "agent platform", "agents API", "agent session", "agent environment", "agent vault", "upload skill", "attach skill", "/v1/agents", "/v1/skills", or wants to spin up an autonomous agent that runs on Anthropic's managed infrastructure with connectors and skills.

Agent Builder

Build Anthropic Managed Agents through a friendly, non-technical conversation. The user picks what they want; this skill quietly translates it into the right API calls.

When This Skill Loads

1. Silently read every file in `references/`. Do not narrate this. 2. Do not list "Step 1, Step 2, …" in chat. Do not paste raw JSON, curl commands, or API field names into the user's view. Those exist only in the references for your own use. 3. Start the conversation with a single warm sentence, then drop straight into the first question via `AskUserQuestion`.

Opener (example, vary as needed): > "Let's build your agent. A few quick questions and I'll set everything up for you."

How To Drive The Conversation

Every branching question MUST go through `AskUserQuestion`, never plain chat. Plain chat is reserved for short confirmations and the final summary. Use the descriptions inside each option to teach the concept (what a connector is, what a skill is, etc.) so the user never has to know the underlying terms.

Run the questions in this order. Skip a question if the user already volunteered the answer earlier in the conversation.

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Q1. What kind of agent are you building?

Use `AskUserQuestion`. Header: `Agent type`. Options (single-select):

• **Research & analysis**. Reads sources on the web or in your tools, summarizes, finds patterns.
• **Content creation**. Drafts posts, emails, scripts, documents.
• **Operations & automation**. Handles tasks across your apps (Slack, Notion, CRM, etc.).
• **Custom**. Describe it yourself.

If "Custom", follow up with a single open question: "In one sentence, what should this agent do?"

Internally, use the answer to seed a short `system` prompt. The user never sees the word "system prompt".

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Q2. Which apps should it connect to?

First, in chat, explain in one sentence: > "Connectors are the apps your agent can read from and act on, like Slack, Gmail, or Notion. Pick whichever this agent needs."

Then use `AskUserQuestion` with `multiSelect: true`. Header: `Connectors`. Options:

• **Slack**. Read channels, send messages, search history.
• **Notion**. Read pages, create or update notes.
• **Gmail / Google Workspace**. Read and send mail, work with Drive, Calendar.
• **GitHub**. Read issues, comment on PRs, browse code.

If the user names something not in the list (e.g. Stripe, Linear, HubSpot, Calendly, Intercom), accept it as another connector to add. Do NOT ask the user for the MCP server URL. You find it yourself.

Finding the MCP URL for a connector

For every connector picked (preset or user-named), resolve the official remote MCP endpoint by web search. Do this silently in the background; do not show search results in chat. Use `WebSearch` (or the available web search tool) with a query like `"<connector> official remote MCP server URL"` and prefer hits from:

1. The vendor's own docs (e.g. `stripe.com/docs/mcp`, `developers.notion.com/docs/mcp`). 2. Anthropic's connector directory. 3. The MCP registry (`https://mcp.so` or `https://pulsemcp.com`).

If web search returns nothing trustworthy after two tries, then (and only then) ask the user once for the URL. Never invent or guess a URL.

Default URLs you can use without searching (only if exact match):

• Gmail / Google Workspace → use the Anthropic-hosted Google Workspace connector URL discovered via the directory.
• Slack → `https://mcp.slack.com/mcp`
• GitHub → `https://api.githubcopilot.com/mcp/`
• Stripe → `https://mcp.stripe.com/`

Registering the connector

For every selected connector, internally: 1. Add `{ "type": "url", "name": <slug>, "url": <resolved_url> }` to `mcp_servers`. 2. Add a matching `{ "type": "mcp_toolset", "mcp_server_name": <slug>, ... }` to `tools`.

**Do not collect any access tokens or OAuth credentials in this flow.** The agent is built with MCP servers attached but no vault credentials. The user authorizes each connector later in the Anthropic dashboard (OAuth flow there). When you create the vault in the build phase, create it empty.

In the final summary, tell the user clearly which connectors still need to be authorized, and link them to where they do it. Example one-liner: "You'll need to authorize Gmail and Stripe once in the Anthropic console before the agent can use them."

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Q3. What core abilities should it have?

Explain in one sentence: > "These are the built-in things the agent can do on its own without needing an outside app."

Use `AskUserQuestion`, `multiSelect: true`. Header: `Abilities`. Options:

• **Work with files**. Read, write, and edit files in its workspace.
• **Run code**. Execute bash commands and scripts.
• **Search the web**. Look things up online.
• **Open web pages**. Fetch and read specific URLs.

Internally map to the `agent_toolset_20260401` `configs` array: enable `read`/`write`/`edit`/`glob`/`grep` for files, `bash` for code, `web_search`, `web_fetch`. Anything not picked is disabled.

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Q4. Should it work with documents?

Use `AskUserQuestion`, `multiSelect: true`. Header: `Documents`. Options:

• **Spreadsheets**. Excel files (x