feat(mcp): support UI metadata for tool registration

[lighte-chen]

Summary

• add typed meta.ui configuration to MCPTool
• preserve TEGG-facing meta and map it to MCP SDK _meta during tool registration
• support both controller plugin and standalone service worker runtimes

Testing

• focused controller decorator metadata test
• focused controller plugin MCP registration test
• focused service worker MCP tool listing test
• tsc:pub for tegg-types, controller-decorator, controller plugin, and service worker
• repository npm run lint

Summary by CodeRabbit

• New Features

  • MCP tool registrations can now include optional UI metadata, including a resourceUri and visibility (limited to model/app).
  • This UI metadata is preserved during registration and returned when tools are listed, enabling more reliable UI discovery.

• Tests

  • Expanded tool-listing assertions to deep-verify each tool’s returned UI metadata (resourceUri and visibility).

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: ca5fd934-4260-49ec-86e2-995f22343423

📥 Commits

Reviewing files that changed from the base of the PR and between b62d634 and 73eb7d3.

📒 Files selected for processing (9)

• core/controller-decorator/src/model/MCPToolMeta.ts
• core/controller-decorator/test/MCPMeta.test.ts
• core/controller-decorator/test/fixtures/MCPController.ts
• core/types/controller-decorator/MCPToolParams.ts
• plugin/controller/lib/impl/mcp/MCPServerHelper.ts
• plugin/controller/test/mcp/helper.test.ts
• standalone/service-worker/src/mcp/MCPServerHelper.ts
• standalone/service-worker/test/fixtures/mcp/MCPTestController.ts
• standalone/service-worker/test/mcp/mcp.test.ts

🚧 Files skipped from review as they are similar to previous changes (8)

• standalone/service-worker/test/mcp/mcp.test.ts
• core/controller-decorator/test/fixtures/MCPController.ts
• core/controller-decorator/test/MCPMeta.test.ts
• plugin/controller/lib/impl/mcp/MCPServerHelper.ts
• plugin/controller/test/mcp/helper.test.ts
• standalone/service-worker/test/fixtures/mcp/MCPTestController.ts
• standalone/service-worker/src/mcp/MCPServerHelper.ts
• core/controller-decorator/src/model/MCPToolMeta.ts

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📝 Walkthrough

Walkthrough

MCP tool definitions now support optional UI metadata. MCPToolMeta retains the metadata, and both MCP server helpers forward it as _meta during tool registration. Tests verify the metadata in local tool models and MCP tool listings.

Changes

MCP metadata propagation

Layer / File(s)	Summary
Metadata contract and decorator retention core/types/controller-decorator/MCPToolParams.ts, core/controller-decorator/src/model/MCPToolMeta.ts, core/controller-decorator/test/*	Adds typed UI metadata to MCP parameters, retains it in tool metadata, and validates decorator metadata.
Plugin MCP registration plugin/controller/lib/impl/mcp/MCPServerHelper.ts, plugin/controller/test/mcp/helper.test.ts	Passes tool metadata as _meta during registration and verifies it through listTools().
Standalone service-worker registration standalone/service-worker/src/mcp/MCPServerHelper.ts, standalone/service-worker/test/*	Forwards tool metadata as _meta and verifies the listed echo tool metadata.

Estimated code review effort: 2 (Simple) | ~10 minutes

Sequence Diagram(s)

sequenceDiagram
  participant MCPTool
  participant MCPToolMeta
  participant MCPServerHelper
  participant MCPClient
  MCPTool->>MCPToolMeta: define meta.ui metadata
  MCPToolMeta->>MCPServerHelper: retain toolMeta.meta
  MCPServerHelper->>MCPClient: registerTool with _meta
  MCPClient->>MCPClient: listTools returns _meta

Loading

Possibly related PRs

• eggjs/tegg#321: Refactors the MCP server helper registration path touched by this metadata forwarding change.
• eggjs/tegg#334: Refactors the MCP registration options path and related MCP tool parameter typing used by this change.

Suggested reviewers: killagu

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title is concise and accurately summarizes the main change: adding UI metadata support to MCP tool registration.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

Warning

There were issues while running some tools. Please review the errors and either fix the tool's configuration or disable the tool if it's a critical failure.

🔧 ESLint

If the error stems from missing dependencies, add them to the package.json file. For unrecoverable errors (e.g., due to private dependencies), disable the tool in the CodeRabbit configuration.

core/controller-decorator/src/model/MCPToolMeta.ts

ESLint skipped: missing config or dependency (missing-dependency). The ESLint configuration references a package that is not available in the sandbox.

core/controller-decorator/test/MCPMeta.test.ts

ESLint skipped: the ESLint configuration for this file references a package that is not available in the sandbox.

core/controller-decorator/test/fixtures/MCPController.ts

ESLint skipped: the ESLint configuration for this file references a package that is not available in the sandbox.

• 6 others

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[gemini-code-assist]

Code Review

This pull request introduces support for metadata configuration in MCP tools by adding a meta property to MCPToolParams and propagating it during tool registration in both the controller plugin and standalone service worker. The review feedback suggests improving the extensibility of MCPToolRegistrationMeta by making the ui property optional and allowing arbitrary key-value pairs.

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[akitaSummer]

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