MCP tools, resources, and prompts in plain language

MCP provides a common way for a service and an AI application to exchange useful capabilities and context. When reading an integration's documentation, you may see tools, resources, and prompts. They serve different purposes, and understanding the distinction makes a connection easier to evaluate.

Think about the job of each piece

A tool exposes an operation the service can perform. A resource supplies information or context that can be read. A prompt provides a reusable starting structure for a task. The exact behavior depends on the implementation, and a tool can be read-only or have effects. Names alone do not establish the risk or permissions.

For a hypothetical rental integration, a resource might describe operating rules, a tool might list repair records, and a prompt might guide a weekly review. A separate operation that changes a financial record would need a much stronger execution and approval process. The AI should discover the current contract rather than assume that a familiar tool name always has the same behavior.

Read the contract before relying on it

• What does the operation accept and return?
• Which account and records are in scope?
• Does it read information, create a draft, or commit a change?
• What review or approval is required?
• How do retries and uncertain outcomes work?

A reusable prompt is useful guidance, but it cannot grant access that the service has not authorized. Likewise, a tool description saying an action is safe does not replace the service's actual controls.

A weekly-review example

The AI reads the service's operating guidance, retrieves the permitted open repairs, and produces a summary. You can verify that the summary matches the returned records. If it then proposes a message or a financial action, that is a new step with its own authority and evidence requirements.

Keep the standard and the product separate

MCP is the connection standard. The connected product is responsible for its own data model, authorization, accuracy, and effects. A product name containing MCP does not prove a working integration exists. Consult both the official protocol documentation and the service's current capability description before deciding what a connection can do for your work.