Agent Builder gives your AI assistants real capabilities — the ability to read, write, search, and take action on your WordPress site. This page explains how the capability layers fit together.
The Capability Stack
Every action an assistant takes flows through a layered architecture. Each layer adds a specific type of capability:
agent-builder/ namespace. Enables cross-plugin AI interoperability.
How They Fit Together
Skills instruct, Tools execute
A skill never takes action directly. It teaches the agent reasoning patterns: “When a user asks to hand off to a human, use the Slack escalation tool.” The tool is what actually sends the Slack message. You can import skills from the community to make your agents smarter without writing code.
Channels extend, Tools power
A channel connects an agent to an external platform (WhatsApp, Email, Slack). Under the hood, channels register their own tools — send_whatsapp_message, send_email — that the agent calls when needed. Skills teach agents when and how to use channel-specific tools effectively.
WordPress Abilities & MCP bridge the ecosystem
The WordPress Abilities API (WP 6.9+) publishes your agent’s tools as native WordPress capabilities, so other plugins can discover and use them. MCP exposes them to external AI clients — Claude Desktop, Cursor, or any MCP-compatible tool — making your WordPress site an AI-powered API.
Dependency Map
| Layer | Depends On | Required? |
|---|---|---|
| Agent | Tools (at minimum) | Yes — core |
| Skills | Agent + Tools | Optional enhancement |
| Tools | Agent Builder plugin | Yes — core |
| Channels | Agent + Tools + API credentials | Optional (Premium) |
| WP Abilities | WordPress 6.9+ + Agent Builder | Automatic if WP 6.9+ |
| MCP | Agent Builder + WP-CLI access | Optional (Premium) |
Quick Start by Role
Site Owner
Install the plugin, activate an assistant, and start chatting. Tools are pre-configured — no setup needed.
Quick Start Guide →Power User
Import community skills to teach your agents new workflows. Toggle individual tools on/off per assistant.
Browse Tools →Developer
Build custom tools and skills. Connect agents to WhatsApp, Email, or Slack. Expose agents via MCP for Claude and Cursor.
MCP Integration →Capability Types Explained
Tools are PHP functions that an AI assistant can call during a conversation. Each tool has a name, a description, and a set of typed parameters. The LLM reads the description to decide when to invoke the tool. Examples include get_post (reads a WordPress post), create_post (publishes new content), run_query (queries the database), and send_email (sends a notification). Tools are the foundation of every capable agent.
Skills are SKILL.md instruction files that are injected into an agent’s system prompt at runtime. A skill does not execute code — it teaches the agent reasoning patterns. For example, a “customer escalation” skill might instruct the agent: “When a user expresses frustration, acknowledge the issue, offer to escalate to a human, and use the Slack tool to notify the support team.” Skills are importable from the community marketplace and can be applied to any agent without writing code.
Channels connect agents to external communication platforms. The WhatsApp channel lets a WordPress AI agent receive and reply to WhatsApp messages. The Email channel processes inbound emails and sends replies. The Slack channel posts messages and reads channel history. Each channel registers its own tools under the hood, so the agent can use send_whatsapp_message or send_email the same way it uses any other tool.
The WordPress Abilities API (available in WordPress 6.9+) publishes your agent’s tools as native WordPress abilities under the agent-builder/ namespace. Other plugins that support the Abilities API can then discover and call your agent’s tools — enabling cross-plugin AI collaboration without custom integrations.
MCP (Model Context Protocol) turns each Agent Builder agent into an MCP server. External tools like Claude Desktop, VS Code with Continue, and Cursor can connect to your WordPress site via STDIO or HTTP transport and call your agent’s tools directly. This effectively makes your WordPress installation an AI-powered API that any MCP client can use.
Frequently Asked Questions
Do I need to understand all capability layers to use Agent Builder?
No. For most site owners, you only need to think about Tools. Install the plugin, activate an assistant, and its tools are pre-configured. Skills, Channels, MCP, and the WordPress Abilities API are advanced features for power users and developers who want to extend the platform beyond the defaults.
What is the difference between a tool and a skill?
A tool is an action — a PHP function the agent can call to read or write data on your site. A skill is a set of instructions — it tells the agent when and how to use tools in specific situations. Tools are the hands of the assistant; skills are the training that guides those hands. You can have a fully functional agent with tools and no skills. Skills make agents smarter and more reliable for specific workflows without requiring code changes.
Are all capabilities available on the free plan?
The core tool set is available on all plans including free. Channels (WhatsApp, Email, Slack), MCP integration, and advanced tool categories require a Premium licence. The WordPress Abilities API is available on all plans as it relies on WordPress core functionality. You can see which tools are active for your plan in Settings → Agents → Chat Feature Overrides.
Can I build my own tools and skills?
Yes. Custom tools are built in PHP by extending the AgenticAgent_Base class and registering tool callbacks. Custom skills are SKILL.md files you write in plain text and upload to your agent. Both can be packaged and submitted to the Agent Marketplace so other WordPress site owners can install and benefit from them. See the Developer Guidelines and Building a Custom Agent for full instructions.
How does MCP differ from the REST API?
The WordPress REST API is designed for HTTP clients — apps and scripts that make authenticated requests to read or write data. MCP is designed for AI clients — tools like Claude Desktop or Cursor that need to discover what actions are available and call them using the Model Context Protocol standard. MCP provides a structured tool manifest (what the agent can do) plus execution (calling those tools), all in a format that LLMs are built to work with. The two APIs serve different consumers and different use cases.
Does enabling MCP expose my WordPress site to security risks?
MCP access requires authentication — MCP clients must provide a valid WordPress application password or API key scoped to the agent. You control which tools are exposed via MCP on a per-agent basis. Destructive tools (those that delete content or change settings) can be disabled for MCP access independently of their status in the chat interface. See Important Security Settings for the recommended MCP lockdown configuration.