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Dictionary

MCP Resources

MCP resources are addressable read-only context — files, records, docs — that a client can pull into the model instead of calling a tool.

2 min readupdated 2026-08-01

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Resources are identified by URI and fetched on demand, which keeps large context out of the prompt until it is needed. Use resources for material the model reads (documentation, a spec, a record) and tools for actions it performs. Mixing the two into one giant tool is the most common MCP design mistake.

MCP resources are addressable read-only context — files, records, docs — that a client can pull into the model instead of calling a tool. Resources are identified by URI and fetched on demand, which keeps large context out of the prompt until it is needed. Use resources for material the model reads (documentation, a spec, a record) and tools for actions it performs. Mixing the two into one giant tool is the most common MCP design mistake. In practice: A knowledge-base server exposes `kb://policies/refunds` as a resource; the agent pulls it only when a refund question arrives. This dictionary node is part of the Onexial knowledge graph and links to related concepts, workflows and tools below.
Definition
Resources are identified by URI and fetched on demand, which keeps large context out of the prompt until it is needed. Use resources for material the model reads (documentation, a spec, a record) and tools for actions it performs. Mixing the two into one giant tool is the most common MCP design mistake.
Example
A knowledge-base server exposes `kb://policies/refunds` as a resource; the agent pulls it only when a refund question arrives.
Related Workflows
Related Tool Stacks
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What is MCP Resources?

Resources are identified by URI and fetched on demand, which keeps large context out of the prompt until it is needed. Use resources for material the model reads (documentation, a spec, a record) and tools for actions it performs. Mixing the two into one giant tool is the most common MCP design mistake.

What is an example of MCP Resources?

A knowledge-base server exposes `kb://policies/refunds` as a resource; the agent pulls it only when a refund question arrives.

Why does MCP Resources matter for AI and automation?

MCP resources are addressable read-only context — files, records, docs — that a client can pull into the model instead of calling a tool. It connects to the workflows, prompts and tool stacks linked on this page, so you can move from definition to execution without leaving Onexial.

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Related concepts

The vocabulary this page depends on.

  • MCP (Model Context Protocol)

    Open standard letting AI clients call external tools, data and prompts.

  • Context Engineering

    Context engineering is the discipline of deciding exactly what information enters a model's context window, in what order and at what cost.

  • MCP Server

    An MCP server exposes tools, resources and prompts from one system so any MCP-compatible AI client can use them over a standard protocol.

  • MCP Client

    An MCP client is the AI-side host that discovers servers, lists their tools and routes the model's calls to them.

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The tools that run it in production.

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