Grade of incomplete

After months of acrimony the Walsh administration and the Boston Teachers Union have reached a tentative agreement on a contract but nobody should be doing back flips here. The dollars and cents issues may have been resolved but only in the short-term, and a major policy reform was left on the table.

The parties acknowledge this is a short-term agreement and insist they’ll spend the coming months negotiating over the stickier issues — but we’re not sure where the incentive is now for the BTU to go along with reforms it insists are draconian.

Of course we understand the incentive on both sides to get the contract resolved before the school year starts. The union could have leveraged the lack of a contract to pressure Mayor Marty Walsh, who is seeking reelection in November. The BTU had already declared an impasse in negotiations (and made a ludicrous claim of sexism in the city’s failure to reach agreement with a majority-female union).

With raises in hand, and a deal in principle, that pressure is off.

But the school year will once again begin with the fate of unassigned teachers, who are entitled to full pay despite the fact that they don’t have classrooms and may have been determined to be underperforming, still up in the air. That’s the biggest failure of this agreement.

The city had pushed for the authority to terminate those teachers, or at a minimum to change their status to paraprofessional if they are unable to lock down a classroom within two years. The union has fought that change tooth and nail.

And yes, it’s one of the great curiosities about collective bargaining — why a union would go scorched earth to protect 2 percent of its members, who don’t perform as well as their peers. Pay and benefits for those teachers cost nearly $8 million in the last fiscal year.

But hey, it worked. And we’re not at all confident that this issue will be addressed in the next round of negotiations; more likely those teachers who remain in the unassigned pool will simply be permitted to run out the clock.

On the up side, taxpayers ought to be grateful that a mediator wasn’t the one making the final call on this agreement. The raises are reasonable. The two parties agreed to strengthen the ability of principals to hire teachers without regard for their seniority.

But without the most important cost-saving reform, the contract gets an incomplete.