Add resource://mapbox-documentation with proper MIME type support

[mattpodwysocki]

Summary

Adds resource://mapbox-documentation as a proper MCP resource with text/markdown MIME type, while keeping the existing get_latest_mapbox_docs_tool for broad compatibility.

Why This Matters

Following up on PR #58 which added the Accept header, this PR provides the full solution for clients that properly support MCP resources:

Tool (get_latest_mapbox_docs_tool):

• Returns type: 'text' (no MIME type)
• Works everywhere
• Easy to discover and call

Resource (resource://mapbox-documentation):

• Returns mimeType: 'text/markdown' (properly typed)
• For clients that support resources well
• Follows same pattern as our other reference resources

Changes

New Files:

• src/resources/mapbox-documentation-resource/MapboxDocumentationResource.ts - Resource implementation
• test/resources/mapbox-documentation-resource/MapboxDocumentationResource.test.ts - Comprehensive tests

Modified Files:

• src/resources/resourceRegistry.ts - Register new resource
• src/tools/get-mapbox-doc-source-tool/GetMapboxDocSourceTool.ts - Updated description to mention resource
• src/tools/get-reference-tool/GetReferenceTool.ts - Fixed TypeScript type assertion
• test/tools/__snapshots__/tool-naming-convention.test.ts.snap - Updated snapshot

Implementation Details

The MapboxDocumentationResource:

• Fetches from https://docs.mapbox.com/llms.txt
• Uses Accept header from PR Add Accept header for documentation fetching #58 (text/markdown, text/plain;q=0.9, */*;q=0.8)
• Returns with proper mimeType: 'text/markdown'
• Handles errors consistently with other resources

Testing

• ✅ All 520 tests pass (5 new tests added)
• ✅ Build succeeds with no TypeScript errors
• ✅ Tool description updated to guide users to resource when appropriate
• ✅ Follows same pattern as existing resources

User Experience

Users now have two ways to access documentation:

1. Call the tool (works everywhere):

   get_latest_mapbox_docs_tool({})

2. Read the resource (better typing):

   // Client reads resource://mapbox-documentation

The tool description mentions the resource for clients that support it:

"For clients that support resources, use resource://mapbox-documentation for proper text/markdown MIME type support."

Consistency

This follows the same pattern we use with:

• resource://mapbox-style-layers
• resource://mapbox-streets-v8-fields
• resource://mapbox-token-scopes
• resource://mapbox-layer-type-mapping

The key difference is that this resource fetches from an external URL (docs.mapbox.com) rather than returning static content, making it always up-to-date.

[mattpodwysocki]

Manual Testing in MCP Inspector

Verified the implementation works correctly in MCP Inspector:

✅ Resource appears in Resources list as "Mapbox Documentation"
✅ Returns content with proper mimeType: "text/markdown"
✅ Successfully fetches documentation from docs.mapbox.com/llms.txt
✅ Content displays correctly with full markdown formatting

Screenshot shows the resource returning structured data with:

• uri: "resource://mapbox-documentation"
• mimeType: "text/markdown" (properly typed!)
• text: "# Mapbox Documentation..." (full content)

This confirms that clients supporting resources will get proper MIME type information, while the tool continues to work for all clients.