/*
 * Copyright 2008-2026 Async-IO.org
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package org.atmosphere.mcp.annotation;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * Marks a method as an MCP tool. The method will be invocable by MCP clients
 * via {@code tools/call}. Parameters should be annotated with {@link McpParam}.
 *
 * <pre>{@code
 * @McpTool(name = "search", description = "Search the knowledge base")
 * public List<Result> search(@McpParam(name = "query", required = true) String query) {
 *     return knowledgeBase.search(query);
 * }
 * }</pre>
 */
@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface McpTool {

    /** Tool name as reported to MCP clients. Programmatic identifier. */
    String name();

    /**
     * Human-friendly display title (MCP 2025-06-18+). Use this for UI labels
     * so {@link #name()} stays a stable programmatic identifier. Defaults to
     * empty, in which case the response omits the {@code title} field.
     */
    String title() default "";

    /** Human-readable description of what this tool does. */
    String description() default "";

    /**
     * Optional icon URI advertised in tools/list (MCP 2025-11-25). Empty
     * string omits the {@code icons} field from the wire response.
     */
    String iconUrl() default "";
}
