A stakeholder request is not a spec — it's a wish. Handed straight to a coding agent, a vague request burns the agent's whole effort on guessing what you meant instead of building it. Researchers building agent-computer interfaces landed on the fix: agents are a new kind of user, and the spec is their interface — build it for them, not for a person who could just ask a follow-up question in the hallway.
A spec an agent can execute has three things a wish doesn't: exactly what to build, exactly what's out of scope, and exactly how you'll know it's done. Skip any one of those and the agent fills the gap with its best guess — which is rarely your best guess.
Run the seed: take a vague stakeholder request and rewrite it into a spec with all three pieces. Notice how much shorter the actual build gets once the guessing is gone.