---
title: "Check Tool examples against their schemas"
description: "Example input must satisfy the resolved inputSchema, and successful structured output must satisfy outputSchema when supplied. Correct the example or the declaration's schema. Wher"
source: "https://mcpdesc.org/docs/rules/0.9.0-rc.3/mcpdesc/tool-example-schema-conformance/"
---

Example input must satisfy the resolved inputSchema, and successful structured output must satisfy outputSchema when supplied. Correct the example or the declaration’s schema. Where resolution or dialect support prevents complete checking, the diagnostic must make that limitation visible.

## Requirement

A Tool example input validates against inputSchema, and its structuredContent against outputSchema, for every applicable protocol version; incomplete validation is reported.

## Details

**Rule ID:** `mcpdesc.tool.example.schema-conformance`  
**Owner:** mcpdesc  
**Surface:** Tool example · **Path:** `examples, interactionExamples`  
**Kind:** mcpdesc-semantic  
**Requirement level:** must  
**Status:** internal · **Enforcement:** internal

## Protocol version applicability

| 2024-11-05 | 2025-03-26 | 2025-06-18 | 2025-11-25 | 2026-07-28 |
| ---------- | ---------- | ---------- | ---------- | ---------- |
| applies    | applies    | applies    | applies    | applies    |

## Required by

* **MCP Description 0.9.0, Sections 9.2, 9.3, and 9.4**  
  * 9\. Tools: [req-tool-example-input-valid](https://mcpdesc.org/docs/specification/0.9.0-rc.3/tools#req-tool-example-input-valid)
  * 1. Tools: [req-tool-example-incomplete-validation](https://mcpdesc.org/docs/specification/0.9.0-rc.3/tools#req-tool-example-incomplete-validation)

## Based on

* **Tier 1 — MCP schema.ts and normative specification text:** MCP 2025-06-18 to 2026-07-28 specification, Server Features, Tools, Output Schema (structured results conform to outputSchema)  
  * <https://github.com/modelcontextprotocol/modelcontextprotocol/blob/dae694f61a31f7a3ec2af3aff709e11f70f61e48/docs/specification/2025-06-18/server/tools.mdx#L309-L382>
  * <https://github.com/modelcontextprotocol/modelcontextprotocol/blob/dae694f61a31f7a3ec2af3aff709e11f70f61e48/docs/specification/2025-11-25/server/tools.mdx#L335-L408>
  * <https://github.com/modelcontextprotocol/modelcontextprotocol/blob/dae694f61a31f7a3ec2af3aff709e11f70f61e48/docs/specification/2026-07-28/server/tools.mdx#L509-L631>

## Notes

Before MCP 2025-11-25 no embedded dialect is defined, so only the legacy shape is checked and the warning reports the gap.

## Examples

### Accepted with a warning

Source: [expected-warning/pre-dialect-tool-example.json](https://github.com/mcpdesc/mcpdesc-specification/blob/v0.9.0-rc.3/spec/draft/fixtures/expected-warning/pre-dialect-tool-example.json) · Selected: `/tools/0/examples/friendly`

```json
{
  "input": {
    "name": "Example User"
  },
  "result": {
    "content": [
      {
        "type": "text",
        "text": "Hello, Example User."
      }
    ]
  }
}
```

### Accepted with a warning

Source: [expected-warning/unresolved-external-tool-example-ref.json](https://github.com/mcpdesc/mcpdesc-specification/blob/v0.9.0-rc.3/spec/draft/fixtures/expected-warning/unresolved-external-tool-example-ref.json) · Selected: `/tools/0/examples/external-identifier`

```json
{
  "input": {
    "identifier": "example-123"
  },
  "result": {
    "resultType": "complete",
    "content": [
      {
        "type": "text",
        "text": "Found example-123."
      }
    ]
  }
}
```

### Invalid example

Source: [expected-invalid/tool-example-schema-mismatches.json](https://github.com/mcpdesc/mcpdesc-specification/blob/v0.9.0-rc.3/spec/draft/fixtures/expected-invalid/tool-example-schema-mismatches.json) · Selected: `/tools/0/examples/wrong-types`

```json
{
  "input": {
    "count": "one"
  },
  "result": {
    "resultType": "complete",
    "content": [
      {
        "type": "text",
        "text": "one"
      }
    ],
    "structuredContent": {
      "total": "one"
    }
  }
}
```

### Invalid example

Source: [expected-invalid/component-contextual-examples.json](https://github.com/mcpdesc/mcpdesc-specification/blob/v0.9.0-rc.3/spec/draft/fixtures/expected-invalid/component-contextual-examples.json) · Selected: `/components/toolExamples/bad-input`

```json
{
  "input": {
    "query": 42
  },
  "result": {
    "resultType": "complete",
    "content": [],
    "structuredContent": {
      "count": "one"
    }
  }
}
```

## Rule Source Code

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