My MCP Server Only Talks to APIs I Trust. That Doesn't Mean the Data Coming Back Is Trustworthy.

I built a small MCP server a while back — developer-presence, seven tools wrapping the GitHub REST API and the DEV.to API so an agent can check my repo stats, list my articles, or draft a new post without me leaving the chat. It's mine, I wrote every line, there's no third-party package doing anything sketchy under the hood. By the usual "vet your MCP servers before installing them" checklist, it passes clean. I've written that checklist article before.

What I hadn't thought carefully about until recently is that vetting the server doesn't vet the data. Two of its tools go straight to the point:

@mcp.tool()

def get_repo_stats(repo: str) -> dict:

"""Get stars, forks, watchers, open issues for enjoykumawat/<repo>."""