ModusToolbox AI Assistant vs Ref

ModusToolbox AI Assistant

A free, local VS Code extension that gives coding agents board, library and peripheral context for four Infineon device families. Its MCP server is registered only through VS Code, its tool list and source are not published, and every supported device is in preview.

Ref

Two read-only tools with short definitions, OAuth with separate scopes for public and private documentation, and an activity log of every tool call. The API key may be passed in the URL query string, no rate limit or 429 guidance is documented, and the free allowance is 200 one-time credits.

ModusToolbox AI Assistant

1. Expect this only inside VS Code, with ModusToolbox 3.7 or later, Python 3.9 or later and the ModusToolbox for VS Code extension installed.
2. Read .github/skills/mtb-* and .github/copilot-instructions.md for board-specific guidance; they are plain Markdown any agent in the workspace can open.
3. Run Reset MCP Cache or Generate AI Instructions when the guidance does not match the active board.
4. Check the board is PSOC Edge E84, PSOC Control C3, PSOC 4 HV or TRAVEO T2G before relying on it; PSOC 6 and PSOC 4 are not supported yet.

Ref

1. Send the key in the x-ref-api-key header, not the ?apiKey= query parameter, so it stays out of URLs and logs
2. Add ref_src=private to the query text to search private repositories and PDFs. Searches cover public documentation only by default
3. Pass ref_read_url the exact URL from a search result. Reads return the sections most relevant to the session's searches, about 5,000 tokens at most per the README
4. Keep one MCP session per task. Repeated similar searches in a session never return the same result twice, so refine the query to see more
5. Treat tool errors as text. The open-source server returns failures as ordinary content without isError