Add icons property to Data Types sections in specification docs

The icons property was already shown in JSON examples but was missing
from the formal Data Types documentation for Prompt, Resource, and Tool.

Fixes modelcontextprotocol#1967

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: jonathanhefner

docs/specification/2025-11-25/server/prompts.mdx

@@ -184,6 +184,7 @@ A prompt definition includes:
 - `name`: Unique identifier for the prompt
 - `title`: Optional human-readable name of the prompt for display purposes.
 - `description`: Optional human-readable description
+- `icons`: Optional array of icons for display in user interfaces
 - `arguments`: Optional list of arguments for customization
 
 ### PromptMessage

docs/specification/2025-11-25/server/resources.mdx

@@ -289,6 +289,7 @@ A resource definition includes:
 - `name`: The name of the resource.
 - `title`: Optional human-readable name of the resource for display purposes.
 - `description`: Optional description
+- `icons`: Optional array of icons for display in user interfaces
 - `mimeType`: Optional MIME type
 - `size`: Optional size in bytes
 

docs/specification/2025-11-25/server/tools.mdx

@@ -193,6 +193,7 @@ A tool definition includes:
 - `name`: Unique identifier for the tool
 - `title`: Optional human-readable name of the tool for display purposes.
 - `description`: Human-readable description of functionality
+- `icons`: Optional array of icons for display in user interfaces
 - `inputSchema`: JSON Schema defining expected parameters
   - Follows the [JSON Schema usage guidelines](/specification/2025-11-25/basic#json-schema-usage)
   - Defaults to 2020-12 if no `$schema` field is present

docs/specification/draft/server/prompts.mdx

@@ -184,6 +184,7 @@ A prompt definition includes:
 - `name`: Unique identifier for the prompt
 - `title`: Optional human-readable name of the prompt for display purposes.
 - `description`: Optional human-readable description
+- `icons`: Optional array of icons for display in user interfaces
 - `arguments`: Optional list of arguments for customization
 
 ### PromptMessage

docs/specification/draft/server/resources.mdx

@@ -289,6 +289,7 @@ A resource definition includes:
 - `name`: The name of the resource.
 - `title`: Optional human-readable name of the resource for display purposes.
 - `description`: Optional description
+- `icons`: Optional array of icons for display in user interfaces
 - `mimeType`: Optional MIME type
 - `size`: Optional size in bytes
 

docs/specification/draft/server/tools.mdx

@@ -193,6 +193,7 @@ A tool definition includes:
 - `name`: Unique identifier for the tool
 - `title`: Optional human-readable name of the tool for display purposes.
 - `description`: Human-readable description of functionality
+- `icons`: Optional array of icons for display in user interfaces
 - `inputSchema`: JSON Schema defining expected parameters
   - Follows the [JSON Schema usage guidelines](/specification/draft/basic#json-schema-usage)
   - Defaults to 2020-12 if no `$schema` field is present