One solution would be to create a model in ModelBuilder. You can drag and drop your two tools into the model and then connect them how you like depending on your workflow i.e. output from Tool 1 becomes input for Tool 2.
If, as it sounds in your case, the user is specifying a parameter for Tool 1 which you want to also use in Tool 2, then in your model you can create a variable (Right-click in ModelBuilder window and select Create Variable), let's call it InVar, which will hold the users input. You will have to choose a type for this variable e.g. Feature Class, SQL Expression, Folder etc.
You can then connect this InVar to Tool 1 and Tool 2 and select which parameter it will become for each tool e.g. Output Dataset, Expression, Output Folder. This will depend on what you're parameters are for your two tools.
Next you have to define the parameters for your model so that when run it prompts the user to assign values to these parameters via a dialogue box - just like other tools.
Right-click on a model element (e.g. Input/Output Dataset or InVar) and choose Model Parameter to make it a parameter - the letter 'P' will appear above the element. In this case, make InVar a parameter.
When happy with your model save it in a toolbox. To run the model double-click the tool you have just made and you will be presented with the usual dialogue box to enter your parameters.
As I don't know the details of your two tools or the workflow it's hard to go into too much detail but that's the gist of it.
For more information (and some tutorials) on ModelBuilder check out the ESRI Resource pages as they provide quite an in-depth look at model building: http://resources.arcgis.com/en/help/main/10.2/#/What_is_ModelBuilder/002w00000001000000/.
In the following graphic I have put together a model in which the output from a tool (Tool 1) becomes the input into another (Tool 2), and I created InVar, a workspace variable, as described above.
Then, using the Connect tool (), I connected InVar to Tool 1 and Tool 2. Since you mention that you wanted InVar to become the workspace environment variable in Tool 2, I selected Environments - Current Workspace when making the connection (as shown in the graphic).
Additionally, I have made Invar and InFeatures Model Parameters as described previously.