LangChain tools vs MCP
LangChain tools are convenient in-process. MCP tools can live as a service boundary with shared ops.
LangChain and similar frameworks ship tool abstractions that run close to your agent code. That is fast to start.
When in-process tools are enough
Single-team prototypes, local scripts, and tools that never leave your process.
When MCP is the better boundary
Multi-agent fleets, shared secrets, central metering, and tools reused by more than one runtime. MCP turns tools into a service you can manage.