A developer builds an MCP server and adds a new tool in application code that runs after the `run()` call. When a connected client requests the capability list, the new tool doesn't appear. What is the cause?
A. The client cached the capability list from a previous session and needs to reconnect to pick up new tools.
B. The tool was registered after run() was called, missing the capability list sent at connection time.
C. The stdio transport doesn't support dynamic tool registration, so the tool must be added via HTTP/SSE instead.
D. The server inspector filters out newly added tools until the server is restarted to prevent session inconsistencies.
Drop your answer (A / B / C / D) in the comments 👇
I'll reveal the correct answer and the why tomorrow.