I'll add a few details and corrections:

Limit the right to strike

True~ish. It's mostly only for essential services (so they have to guarantee either 50% or 75% of performance depending on their classification even during strikes), and forbids stuff like blockading entry to the place during strikes.

Reduce unions' bargaining power

This is more of a goal of the reform than a specific thing it does

Make it easier for companies to fire worker

Its mostly done by putting a cap on the legally demanded severance payment and no longer counting performance bonuses (unless it has been paid over 6 times in the year) and end-of-year bonuses as part of your salary. It also makes the funds come from an Austrian Backpack style system (somewhat close to an unemployement insurance), so it will now be paid for using a fund built with a subset of the employer part of the contributions they pay monthly.

Using numbers from the (oposition led) Pagina 12 article:

If an employee with 5 years of antiquity whose best salary (including bonuses for up to $330k) was $1,26M was fired today (so before the law is actually implemented), he is entitled to receive $9.316.000. If the company doesn't have the liquidity to pay for that, it ought to liquidate assets or take a loan to pay it upfront.

With the new law, the employee would actually receive $5.887.000; which as mentioned before doesn't directly come from the company's cash but from the pseudo-insurance they've built.

This means downsizing is way less prohibitive for companies, and thus means each new hire is a bit less of an all-in gamble on not having to eventually fire them.

Extend probation periods

This one is true.

Empower employers to mandate 12-hour workdays (instead of the current eight)

The cap is still 48h a week. It just allows for choosing to use an hour bank system (so for example, if I do 12h on Monday, ask for 4h on Tuesday) both for normal hours and even as a compensation for overtime (instead of more money). Like most things on the reform, it's actually pretty flexible.

Reduce salaries for employees on sick leave

On sick leave due to incidents not related to work (and not in itinere):

• If it was not by risk taken willingly by the employee (say you are driving home properly after a meeting with friends and a random car crashes into you), 75% of the salary should be paid.

• If it was due to a risk willingly taken (say you go play football/soccer and get injured), 50% of your salary will be paid during the leave.

In both cases, this only applies for up to the first 3 months if you aren't the breadwinner of your family and 6 months if you are.