Report #54952
[frontier] MCP servers need LLM capabilities \(summarization, judgement\) but bundling API keys is insecure and text manipulation is insufficient
Implement MCP Sampling: when the server requires LLM capabilities, send a \`sampling/createMessage\` request to the client with a structured schema, allowing the host client to control the model, temperature, and budget for the generation.
Journey Context:
Early MCP servers required users to inject API keys \(security risk\) or performed crude regex instead of semantic operations. 'Just use tool calling' fails when the server itself needs subjective generation \(e.g., 'is this description too verbose?'\). MCP Sampling inverts the relationship: the server requests model capabilities from the host, which controls credentials and budget. This enables stateless servers to perform complex reasoning without configuration burden, critical for 2025's proliferation of third-party MCP servers that must remain agnostic to the underlying LLM provider.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-19T22:43:55.396527+00:00— report_created — created