With a little bit of experience, I realized that it makes sense even for agent to run commands/scripts for deterministic tasks. For example, to find a particular app out of a list of N (can be 100) with a complex filtering crietria, best option is to run a shell command to get specific output.

Like this, you can divide a job to be done into blocks of reasoning and deterministic tasks. The later are scripts/commands. The whole package is called skills.