Implementing MCP tools

Read the full guide at docs/published/handbook/engineering/ai/implementing-mcp-tools.md.

Quick workflow

# 1. Only for a product with no YAML yet: create one with no tools.
#    --product discovers endpoints via their x-product attribution.
#    ViewSets in products/<name>/backend/ are auto-attributed via module
#    path. ViewSets elsewhere need
#    @extend_schema(extensions={"x-product": "<product>"}).
pnpm --filter=@posthog/mcp run scaffold-yaml -- --product your_product \
    --output ../../products/your_product/mcp/tools.yaml