---
title: "Use a valid Resource Template expression"
description: "Every Resource Template must contain a valid RFC 6570 URI template, even if it has no examples. Correct malformed braces, operators, or variable syntax before checking concrete exp"
source: "https://mcpdesc.org/docs/rules/0.9.0-rc.3/mcp/resource-template-uri-template/"
---

Every Resource Template must contain a valid RFC 6570 URI template, even if it has no examples. Correct malformed braces, operators, or variable syntax before checking concrete expansions. The validator does not retrieve the resulting URI.

## Requirement

A Resource Template uriTemplate is a valid RFC 6570 URI template.

## Details

**Rule ID:** `mcp.resource-template.uri-template`  
**Owner:** mcp  
**Surface:** ResourceTemplate · **Path:** `uriTemplate`  
**Kind:** embedded-standard  
**Requirement level:** must  
**Protocol versions:** independent of the MCP protocol version  
**Status:** internal · **Enforcement:** internal

## Required by

* **MCP Description 0.9.0, Section 10.2.1**  
  * 10\. Resources and Resource Templates: [req-resource-template-uri-template](https://mcpdesc.org/docs/specification/0.9.0-rc.3/resources#req-resource-template-uri-template)

## Based on

* **Tier 1 — MCP schema.ts and normative specification text:** MCP 2024-11-05 to 2026-07-28 schema.ts, interface ResourceTemplate, uriTemplate (“A URI template (according to RFC 6570)”)  
  * [validation/mcp-schemas/2024-11-05/schema.ts#L456-L461](https://github.com/modelcontextprotocol/modelcontextprotocol/blob/dae694f61a31f7a3ec2af3aff709e11f70f61e48/schema/2024-11-05/schema.ts#L456-L461)
  * [validation/mcp-schemas/2025-03-26/schema.ts#L489-L494](https://github.com/modelcontextprotocol/modelcontextprotocol/blob/dae694f61a31f7a3ec2af3aff709e11f70f61e48/schema/2025-03-26/schema.ts#L489-L494)
  * [validation/mcp-schemas/2025-06-18/schema.ts#L570-L575](https://github.com/modelcontextprotocol/modelcontextprotocol/blob/dae694f61a31f7a3ec2af3aff709e11f70f61e48/schema/2025-06-18/schema.ts#L570-L575)
  * [validation/mcp-schemas/2025-11-25/schema.ts#L846-L851](https://github.com/modelcontextprotocol/modelcontextprotocol/blob/dae694f61a31f7a3ec2af3aff709e11f70f61e48/schema/2025-11-25/schema.ts#L846-L851)
  * [validation/mcp-schemas/2026-07-28/schema.ts#L1482-L1487](https://github.com/modelcontextprotocol/modelcontextprotocol/blob/dae694f61a31f7a3ec2af3aff709e11f70f61e48/schema/2026-07-28/schema.ts#L1482-L1487)
* **Tier 2 — Normative referenced standards:** RFC 6570, URI Template  
  * <https://www.rfc-editor.org/rfc/rfc6570#section-3>

## Notes

Reported once per Resource Template, whether or not it has examples; example checks that need the parsed template are skipped.

## Examples

### Invalid example

Source: [expected-invalid/malformed-uri-template-without-examples.json](https://github.com/mcpdesc/mcpdesc-specification/blob/v0.9.0-rc.3/spec/draft/fixtures/expected-invalid/malformed-uri-template-without-examples.json) · Selected: `/resourceTemplates/0`

```json
{
  "uriTemplate": "file:///{path",
  "name": "file_by_path"
}
```

### Invalid example

Source: [expected-invalid/malformed-resource-template-example.json](https://github.com/mcpdesc/mcpdesc-specification/blob/v0.9.0-rc.3/spec/draft/fixtures/expected-invalid/malformed-resource-template-example.json) · Selected: `/resourceTemplates/0`

```json
{
  "uriTemplate": "test://items/{id",
  "name": "malformed_template",
  "examples": {
    "concrete": {
      "uri": "test://items/123",
      "result": {
        "resultType": "complete",
        "contents": [
          {
            "uri": "test://items/123",
            "text": "item"
          }
        ]
      }
    }
  }
}
```

### Invalid example

Source: [expected-invalid/invalid-completion-example-semantics.json](https://github.com/mcpdesc/mcpdesc-specification/blob/v0.9.0-rc.3/spec/draft/fixtures/expected-invalid/invalid-completion-example-semantics.json) · Selected: `/resourceTemplates/0`

```json
{
  "protocolVersions": [
    "2026-07-28"
  ],
  "uriTemplate": "repo://{owner/{repository}/issues/{issue}",
  "name": "broken_template",
  "completionExamples": {
    "bad-template": {
      "argument": {
        "name": "issue",
        "value": "12"
      },
      "result": {
        "resultType": "complete",
        "completion": {
          "values": [
            "120"
          ]
        }
      }
    }
  }
}
```

## Rule Source Code

[resource.yaml](https://github.com/mcpdesc/mcpdesc-specification/blob/v0.9.0-rc.3/spec/draft/validation/rules/resource.yaml) at immutable tag [v0.9.0-rc.3](https://github.com/mcpdesc/mcpdesc-specification/blob/v0.9.0-rc.3/spec/draft).