According to this article, Germany has to rely on some tricks to circumvent the hard limit mentioned in the Constitution:
Germany is considering setting up independent public agencies that could take on new debt to invest in the country’s flagging economy, without falling foul of strict national spending rules, three people familiar with talks about the plan told Reuters.
The creation of new investment agencies would let Germany take advantage of historically low borrowing costs to spend more on infrastructure and climate protection, over and above debt limits enshrined in the constitution, the sources said.
Germany’s debt brake allows a federal budget deficit of up to 0.35% of gross domestic product (GDP). That’s equivalent to about 12 billion euros ($13.3 billion) a year but once factors such as growth rates have been taken into account, Berlin only has the scope to increase new debt by 5 billion next year.
Setting up a hard limit like this in the Constitution is rather strange since one expects that this value has an economical meaning and should change according to the economical context.
Question: Why does Germany have a static "debt brake" value when a value that can be easily changed seems to make more sense?