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The parameters section on each intent lists the parameters required to call the command. For the mail.send command these are the parameters to, from, subject and message. For each command parameter it can be configured whether the AI should auto-detect the value (detect: true, as you can see for the from parameter for example), in this case the description field is mandatory to instruct the AI how to extract the parameter. Or it can be a fixed value (as you can see for the to parameter for example).
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