MCP: add describe tool for Function inspection

[sneharathod7]

Summary

The MCP server currently does not expose a describe tool, even though func describe already exists as a CLI command. After deploying a Function through the MCP workflow, agents do not have a direct MCP-native way to inspect the deployed Function state.

Related to #3646 (LFX: End-to-End Agentic Workflow).

Current Behavior

After deployment, the available MCP workflow is somewhat limited for inspection:

• list provides only high-level Function information
• func://function exposes local func.yaml state rather than live deployment details

This makes it difficult for agents to retrieve deployment-specific information such as:

• route URL
• deployed image
• revision status
• readiness conditions

Expected Behavior

A describe MCP tool should allow agents to inspect deployed Function details such as:

• Function name and namespace
• Runtime and image reference
• Route URL
• Current revision and readiness state
• Additional deployment metadata and conditions

Why This Matters

The current MCP flow supports create → build → deploy, but there is limited support for deployment inspection afterward.

Adding a describe tool would improve the end-to-end workflow by allowing agents to verify and reason about deployed Function state directly through MCP instead of relying on external commands.

Possible Implementation Direction

A new pkg/mcp/tools_describe.go tool could wrap the existing func describe command following the same handler and registration patterns already used by the other MCP tools.

The implementation could support:

• name-based lookup
• path-based lookup
• namespace selection
• optional output formatting

Tool registration and tests could follow the existing MCP tool patterns already present in pkg/mcp.

Notes

• func describe already exists as a CLI command in cmd/describe.go
• describe is a read-only operation and should not require write-enabled MCP mode

[sneharathod7]

/assign