Startup, two tools, ship this quarter
One agent, two tools, a protocol is premature.
Open the live lab · preloaded to this scenario
Protocol Selection Decision Model
Context
A startup has one agent and two tools and needs to ship this quarter. Function calling is enough; an MCP or A2A layer is overhead with no payoff yet.
The decision
Function calling, don't over build. A protocol layer earns its keep at N×M scale, not at two tools and one consumer.
What most miss
Engineers reach for the impressive protocol because it's in the discourse. At this scale it's pure overhead that slows the ship date.
Stakes
Over architecting a two tool agent burns the runway you needed to ship.
Studied · Agent Architecture and Protocol Strategy Artifacts · verified 2026-07-03
Sources: Early-stage agent integration (function calling); Premature-abstraction / over-engineering avoidance