--- a/graal/com.oracle.truffle.api/src/com/oracle/truffle/api/instrument/Probe.java	Mon Aug 18 14:36:12 2014 -0700
+++ b/graal/com.oracle.truffle.api/src/com/oracle/truffle/api/instrument/Probe.java	Mon Aug 18 21:03:41 2014 -0700
@@ -45,9 +45,6 @@
  * attached instruments seldom changes. The assumption is invalidated when instruments are added or
  * removed, but some instruments may change their internal state in such a way that the assumption
  * should also be invalidated.
- * <p>
- * <strong>Disclaimer:</strong> experimental interface under development. In particular, the
- * <em>notify</em> methods must be migrated to another interface.
  *
  * @see Instrument
  * @see Wrapper
@@ -55,27 +52,34 @@
 public interface Probe extends ExecutionEvents, SyntaxTagged {
 
     /**
-     * Get the {@link SourceSection} associated with this probe. This is no longer uniquely
-     * associated.
+     * Get the {@link SourceSection} in some Truffle AST associated with this probe.
      *
      * @return The source associated with this probe.
      */
     SourceSection getSourceLocation();
 
     /**
-     * Mark this probe as being associated with an AST node in some category useful for debugging
-     * and other tools.
+     * Mark this probe as belonging to some tool-related category that can be used to guide tool
+     * behavior at an associated AST node. For example, a debugger might add the tag
+     * {@link StandardSyntaxTag#STATEMENT} as a way of configuring where execution should stop when
+     * stepping.
      */
     void tagAs(SyntaxTag tag);
 
     /**
-     * Adds an instrument to this probe.
+     * Adds an {@link Instrument} to this probe's collection. No check is made to see if the same
+     * instrument has already been added.
+     *
+     * @param newInstrument The instrument to add to this probe.
      */
     void addInstrument(Instrument newInstrument);
 
     /**
-     * Removes an instrument from this probe.
+     * Removes the given instrument from the probe's collection.
+     *
+     * @param oldInstrument The instrument to remove from this probe.
+     * @throws RuntimeException if no matching instrument has been attached.
      */
-    void removeInstrument(Instrument oldInstrument);
+    void removeInstrument(Instrument oldInstrument) throws RuntimeException;
 
 }