Make typed apply method public in MCP Tool base class (#26228)

* Make typed apply method public in MCP Tool base class

The abstract `apply(PermissionHelper, P)` method was protected, limiting
direct invocation of tools with typed parameters to subclasses only.
Widening to public allows other components to reuse tool logic without
needing adapter subclasses solely for visibility.

Co-Authored-By: Claude Opus 4.6 <[EMAIL_ADDRESS_REDACTED]>

* Add changelog

* Remove unnecessary changelog

Author: monrax

graylog2-server/src/main/java/org/graylog/mcp/server/Tool.java

@@ -143,6 +143,7 @@ public Optional<Map<String, Object>> outputSchema() {
      * Calls the tool implementation with the raw parameter map.
      * Internally this will get converted into the actual parameter type for type safety.
      *
+     * @param permissionHelper provides permission checks and user identity for the calling user
      * @param parameterMap raw parameter map
      * @return the return value of the tool call
      */
@@ -151,5 +152,12 @@ public O apply(PermissionHelper permissionHelper, Map<String, Object> parameterM
         return apply(permissionHelper, p);
     }
 
-    protected abstract O apply(PermissionHelper permissionHelper, P parameters);
+    /**
+     * Executes the tool logic with typed parameters and the caller's permission context.
+     *
+     * @param permissionHelper provides permission checks and user identity for the calling user
+     * @param parameters the deserialized, tool-specific parameter object
+     * @return the tool's result, typically a JSON string or structured response object
+     */
+    public abstract O apply(PermissionHelper permissionHelper, P parameters);
 }

graylog2-server/src/main/java/org/graylog/mcp/tools/ListFieldsTool.java

@@ -67,7 +67,7 @@ Fields can have different meanings in different streams (and also per source), s
     }
 
     @Override
-    protected Result apply(final PermissionHelper permissionHelper, final ListFieldsTool.Parameters parameters) {
+    public Result apply(final PermissionHelper permissionHelper, final ListFieldsTool.Parameters parameters) {
         final Set<String> messageStreamIds = permissionHelper.getSearchUser().streams().loadAllMessageStreams();
         Set<String> filteredMessageStreamIds = messageStreamIds;
         if (parameters.streams() != null && !parameters.streams().isEmpty()) {