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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

/ quick answer

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
/ frequently asked

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.