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multiagent/tool_error_middleware.go

@@ -0,0 +1,148 @@
+package multiagent
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/cloudwego/eino/compose"
+	"github.com/cloudwego/eino/schema"
+)
+
+// softRecoveryToolCallMiddleware returns an InvokableToolMiddleware that catches
+// specific recoverable errors from tool execution (JSON parse errors, tool-not-found,
+// etc.) and converts them into soft errors: nil error + descriptive error content
+// returned to the LLM. This allows the model to self-correct within the same
+// iteration rather than crashing the entire graph and requiring a full replay.
+//
+// Without Invokable (+ Streamable where applicable) registration, a JSON parse failure
+// in InvokableRun / StreamableRun propagates as a hard error through the Eino ToolsNode
+// → [NodeRunError] → ev.Err, which
+// either triggers the full-replay retry loop (expensive) or terminates the run
+// entirely once retries are exhausted. With it, the LLM simply sees an error message
+// in the tool result and can adjust its next tool call accordingly.
+func softRecoveryToolCallMiddleware() compose.InvokableToolMiddleware {
+	return func(next compose.InvokableToolEndpoint) compose.InvokableToolEndpoint {
+		return func(ctx context.Context, input *compose.ToolInput) (*compose.ToolOutput, error) {
+			output, err := next(ctx, input)
+			if err == nil {
+				return output, nil
+			}
+			if !isSoftRecoverableToolError(err) {
+				return output, err
+			}
+			// Convert the hard error into a soft error: the LLM will see this
+			// message as the tool's output and can self-correct.
+			msg := buildSoftRecoveryMessage(input.Name, input.Arguments, err)
+			return &compose.ToolOutput{Result: msg}, nil
+		}
+	}
+}
+
+// softRecoveryStreamableToolCallMiddleware mirrors softRecoveryToolCallMiddleware for
+// tools that implement StreamableTool only (e.g. Eino ADK filesystem execute).
+// Eino applies Invokable vs Streamable middleware to disjoint code paths in ToolsNode;
+// registering only Invokable leaves streaming tools uncovered — empty/malformed JSON
+// then fails inside [LocalStreamFunc] before the inner endpoint runs.
+func softRecoveryStreamableToolCallMiddleware() compose.StreamableToolMiddleware {
+	return func(next compose.StreamableToolEndpoint) compose.StreamableToolEndpoint {
+		return func(ctx context.Context, input *compose.ToolInput) (*compose.StreamToolOutput, error) {
+			out, err := next(ctx, input)
+			if err == nil {
+				return out, nil
+			}
+			if !isSoftRecoverableToolError(err) {
+				return out, err
+			}
+			toolName := ""
+			args := ""
+			if input != nil {
+				toolName = input.Name
+				args = input.Arguments
+			}
+			msg := buildSoftRecoveryMessage(toolName, args, err)
+			return &compose.StreamToolOutput{
+				Result: schema.StreamReaderFromArray([]string{msg}),
+			}, nil
+		}
+	}
+}
+
+// softRecoveryToolMiddleware returns a ToolMiddleware with both Invokable and Streamable
+// soft recovery (same semantics as hitlToolCallMiddleware bundling).
+func softRecoveryToolMiddleware() compose.ToolMiddleware {
+	return compose.ToolMiddleware{
+		Invokable:  softRecoveryToolCallMiddleware(),
+		Streamable: softRecoveryStreamableToolCallMiddleware(),
+	}
+}
+
+// isSoftRecoverableToolError determines whether a tool execution error should be
+// silently converted to a tool-result message rather than crashing the graph.
+//
+// Design: default-soft (blacklist). Almost every tool execution error should be
+// fed back to the LLM so it can self-correct or choose an alternative tool.
+// Only a small set of "truly fatal" conditions (user cancellation) should
+// propagate as hard errors that terminate the orchestration graph.
+// This avoids the fragile whitelist approach where every new error pattern
+// would need to be explicitly enumerated.
+func isSoftRecoverableToolError(err error) bool {
+	if err == nil {
+		return false
+	}
+
+	// 用户主动取消 — 唯一应当终止编排的情况，不应重试。
+	if errors.Is(err, context.Canceled) {
+		return false
+	}
+
+	// 其他所有工具执行错误（超时、命令不存在、JSON 解析失败、工具未找到、
+	// 权限不足、网络不可达……）一律转为 soft error，让 LLM 看到错误信息
+	// 后自行决策：换工具、调整参数、或向用户说明。
+	return true
+}
+
+// buildSoftRecoveryMessage creates a bilingual error message that the LLM can act on.
+func buildSoftRecoveryMessage(toolName, arguments string, err error) string {
+	// Truncate arguments preview to avoid flooding the context.
+	argPreview := arguments
+	if len(argPreview) > 300 {
+		argPreview = argPreview[:300] + "... (truncated)"
+	}
+
+	// Try to determine if it's specifically a JSON parse error for a friendlier message.
+	errStr := err.Error()
+	var jsonErr *json.SyntaxError
+	isJSONErr := strings.Contains(strings.ToLower(errStr), "json") ||
+		strings.Contains(strings.ToLower(errStr), "unmarshal")
+	_ = jsonErr // suppress unused
+
+	if isJSONErr {
+		return fmt.Sprintf(
+			"[Tool Error] The arguments for tool '%s' are not valid JSON and could not be parsed.\n"+
+				"Error: %s\n"+
+				"Arguments received: %s\n\n"+
+				"Please fix the JSON (ensure double-quoted keys, matched braces/brackets, no trailing commas, "+
+				"no truncation) and call the tool again.\n\n"+
+				"[工具错误] 工具 '%s' 的参数不是合法 JSON，无法解析。\n"+
+				"错误：%s\n"+
+				"收到的参数：%s\n\n"+
+				"请修正 JSON（确保双引号键名、括号配对、无尾部逗号、无截断），然后重新调用工具。",
+			toolName, errStr, argPreview,
+			toolName, errStr, argPreview,
+		)
+	}
+
+	return fmt.Sprintf(
+		"[Tool Error] Tool '%s' execution failed: %s\n"+
+			"Arguments: %s\n\n"+
+			"Please review the available tools and their expected arguments, then retry.\n\n"+
+			"[工具错误] 工具 '%s' 执行失败：%s\n"+
+			"参数：%s\n\n"+
+			"请检查可用工具及其参数要求，然后重试。",
+		toolName, errStr, argPreview,
+		toolName, errStr, argPreview,
+	)
+}