Ask it, in the tool call itself.
Amplitude's MCP server carries one optional parameter on every tool, called Tool Rationale: a brief explanation of why you are calling this tool. Chanaka Perera's post on consolidating the server reports that agents fill it in about three quarters of the time, unprompted.
The field earned its place on one funnel. Creating a chart took three chained calls. Of 18,703 users who queried data, 20% went on to render a chart and less than 5% saved it. Sequence data alone could not say whether agents wanted only the data or wanted the chart and failed to get there. The rationales on the stalled calls read like "save chart edit for dashboard analysis." Agents were trying to save. Amplitude collapsed the chain into one call.
This corrects something I published. Customer Discovery When Your Customer Is an Agent, from May 2026, says agents don't answer interviews and offers six methods, the first being telemetry and the second being interviews with the human who deployed the agent. Telemetry gives the what. The rationale gives the stated why, at the moment of use, for every customer.
The steps: add the optional parameter, build the funnel across calls, read the rationales where sessions stop, and check each one against what the agent did next, because an agent's account of itself is a claim and not a log.
The full piece is Agents Don't Answer Interviews. Amplitude's Left a Note.