Decision boundary: when MCP is the right abstraction
MCP is useful when several AI hosts need to discover and invoke the same governed capabilities. It is not automatically superior to a direct API for deterministic, high-volume system-to-system traffic. A defensible strategy therefore compares MCP, conventional APIs and workflow automation against the same task, risk and operating model.
Use cases should be classified as informational, preparatory or transactional. Frequency, measurable value, reversibility, data readiness, interface stability and potential harm determine whether a capability belongs in a pilot or must remain outside the model-controlled path.
Evidence required before investment
A decision record needs a baseline, named users, system owners, data classifications, an identity path and explicit stop criteria. A server list or a successful demo is not evidence of production value.
The minimum portfolio artefact records capability purpose, owner, source system, side effects, authorization rule, supported clients, service objective and version. This turns an MCP programme into a governable set of contracts rather than an accumulation of prototypes.