Opening a tool dialog box
The basics of finding a tool and opening its dialog box are covered in A quick tour of executing tools.
Filling in tool parameters
A tool parameter is a simple text string or number that tells the tool what you want it to do. Tool dialog boxes have any number of parameters, and each parameter has its own user interface (UI) control. The most common parameter is the feature class, and its control, shown below, consists of a text box where you can type the path to a feature class and a browse button () that enables you to pick feature classes from disk. The text box will typically have a drop-down list of available layers and table views that you can choose from. You can also drag data onto the parameter.
In most cases, the browse dialog box and drop-down list in a dataset control will only show you valid choices. For example, if the parameter expects a point feature class as input, only point feature classes, and layers based on point features, will be shown as choices.
Other common parameters are preset text strings, called keywords, that you pick from a drop-down list or simple check boxes for Boolean (true/false) parameters. Following are a few examples of parameter controls:
Some tools may group parameters together under a kind of drop-down list. To expose the parameter group, click the down arrows, as shown below:
Optional parameters have default values that are calculated and set by the tool. You can either accept the default value by doing nothing or enter a new value.
Some parameters have more complex user interface controls. One that you're likely to encounter is the multivalue parameter control, which allows you to input lists of things, like a list of feature classes or a list of numbers.
Tools validate parameter values
As you fill in a parameter's control, the tool will validate your input and give you feedback by placing a status icon to the left of the parameter control. Required parameters that don't have a value have a green circle to their left. Invalid values have a red cross, and warnings have a yellow triangle.
You can click the parameter's icon and an information dialog box will appear, which will have an error or warning number. Click the number to open a detailed explanation of the problem and suggestions to fix the problem.
Optional parameters do not have a status icon.
Using layers and table views
When you run a tool in ArcMap, the tool knows about all the layers and tables that are in the ArcMap table of contents, and you can use an ArcMap layer or table in place of a dataset. Layers and tables have selected features and rows, and tools will process only the selected features and rows.
Tools with no output parameters
Most geoprocessing tools take datasets as input and produce new datasets as outputs, so most tool dialog boxes ask you where you want to write the output dataset. However, some will not have a parameter for an output dataset yet still produce output datasets.
The Show Help button exposes the tool dialog box side panel help, which gives a synopsis of the tool and each parameter. For detailed help, click the Show Help >> button to expose the side panel help and click the Tool Help button, as illustrated below. This leads you to the tool's reference page.
When the side panel help is open, you can get help on individual parameters by clicking the parameter control, as shown below. To get back to overview help, click anywhere on the dialog box except for the parameter controls.
Background processing and the Results window
Once you have filled in all parameters correctly, you execute the tool by clicking the OK button.
Tools execute in the background, meaning you can continue working with ArcMap (or other applications, such as ArcGlobe) while the tool executes. You'll see a progress bar at the bottom of your document displaying the name of the currently executing tool. When the tool finishes, a pop-up notification will appear on the system tray.
Learn more about background and foreground processing
You can keep track of tool execution in the Results window. To open the Results window, click Geoprocessing > Results. Using the Results window, you can find out everything about the execution of a tool.
Geoprocessing environment settings
The Environments button displays the Environment Settings dialog box. Environment settings specified will only be used for the current execution of the tool.