In a letter sent to the Crown agency's Chair J. Robert S. Prichard, the city councillor lists off several points that she'd liked answered so that city staff can study the proposed plan.
Earlier this week Transportation Minister Glen Murray said the province would fund the 6.4-kilometre subway extension along the existing Scarborough RT line.
"Minister Murray's plan will be studied by the TTC to ensure that it is technically feasible and to assess any impact on the operation of the extended Bloor-Danforth Line," said Stintz in her letter.
Stintz told CBC News she isn't clear on how the plan will all work, including issues like who pays for busing when the SRT is shut down for construction.
"There's a lot of questions that we need to have answers for before the commission can proceed to study this proposal further," she said.
Among Stintz's requests of Metrolinx is confirmation on whether the province will cover the costs of "overruns" associated with the plan, and also ensure a shutdown of the SRT line would not exceed three years.
Breaking ground in 2018
Metrolinx said construction could start in 2018 and be up and running five years later.
The city and the province had a provincially-funded plan in place to build a seven-stop transit extension in Scarborough using light-rail technology.
City councillors reversed direction in July, opting for a subway extension despite a funding shortfall that would require tax increases, more charges to developers and a federal contribution of about $500 million.
Ottawa has still not announced whether it will help fund the transit project and Transport Minister Lisa Raitt said on Friday that she's heard from Mayor Rob Ford about what he wants, but nothing about the province's new plan.
“They really need to come together and tell us what the local priority is and I hope that happens,” she said.
In an interview with Metro Morning host Matt Galloway on Thursday Murray said the province has over budgeted the cost of the extension by 30 per cent.
But between the city, the provincial government and Metrolinx, transportation expert Ed Levy said it isn't clear who's driving transit planning right now in Toronto.
"There's a tremendous vacuum of leadership, let's be blunt about that, and has been for quite some time,” he said.