WeKnora deployment source with the reviewed wiki identity, summary and recovery fixes

cli/internal/mcp/tools.go

@@ -0,0 +1,713 @@
+package mcp
+
+import (
+	"context"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"io"
+	"strings"
+	"time"
+
+	mcpsdk "github.com/modelcontextprotocol/go-sdk/mcp"
+
+	"github.com/Tencent/WeKnora/cli/internal/cmdutil"
+	"github.com/Tencent/WeKnora/cli/internal/sse"
+	sdk "github.com/Tencent/WeKnora/client"
+)
+
+// toolErrorResult builds an error CallToolResult with IsError=true, a
+// human-readable text fallback (Content), and the error envelope payload
+// (StructuredContent). Reuses cmdutil.ErrorToDetail so the hint / retry /
+// risk / detail fallback table stays single-source.
+//
+// Returns nil when err is nil; callers should only invoke on a real error.
+//
+// CAVEAT (go-sdk v1.6.0): SetError(err) clobbers Content; we manually
+// build CallToolResult instead.
+func toolErrorResult(err error) *mcpsdk.CallToolResult {
+	if err == nil {
+		return nil
+	}
+	detail := cmdutil.ErrorToDetail(err)
+	textLine := detail.Type + ": " + detail.Message
+	if detail.Hint != "" {
+		textLine += "\nhint: " + detail.Hint
+	}
+	if len(detail.RetryArgv) != 0 {
+		textLine += "\nretry: " + strings.Join(detail.RetryArgv, " ")
+	}
+	// StructuredContent accepts any; pass *ErrDetail directly (no round-trip).
+	return &mcpsdk.CallToolResult{
+		IsError:           true,
+		Content:           []mcpsdk.Content{&mcpsdk.TextContent{Text: textLine}},
+		StructuredContent: detail,
+	}
+}
+
+func streamErrorDetail(sessionID, assistantMessageID string) map[string]any {
+	detail := map[string]any{"session_id": sessionID}
+	if assistantMessageID != "" {
+		detail["assistant_message_id"] = assistantMessageID
+	}
+	return detail
+}
+
+func toolStreamError(err *cmdutil.Error, sessionID, assistantMessageID string) *mcpsdk.CallToolResult {
+	return toolErrorResult(err.WithDetail(streamErrorDetail(sessionID, assistantMessageID)))
+}
+
+// successResult builds a CallToolResult with StructuredContent = payload.
+// Using Out=any in all handlers disables the SDK auto-marshal path (which
+// would overwrite our StructuredContent with a zero-struct when the handler
+// returns a typed nil). We manually populate both StructuredContent and a
+// text Content fallback so the shape is identical on success and error.
+func successResult(payload any) *mcpsdk.CallToolResult {
+	return &mcpsdk.CallToolResult{
+		StructuredContent: payload,
+		Content:           []mcpsdk.Content{&mcpsdk.TextContent{Text: marshalToString(payload)}},
+	}
+}
+
+func marshalToString(v any) string {
+	b, _ := json.Marshal(v)
+	return string(b)
+}
+
+// Narrow per-domain service interfaces. ServiceClient (server.go) embeds
+// them all; *sdk.Client satisfies the union implicitly.
+
+type knowledgeBaseService interface {
+	ListKnowledgeBases(ctx context.Context) ([]sdk.KnowledgeBase, error)
+	GetKnowledgeBase(ctx context.Context, id string) (*sdk.KnowledgeBase, error)
+}
+
+type knowledgeService interface {
+	ListKnowledgeWithFilter(ctx context.Context, kbID string, page, pageSize int, filter sdk.KnowledgeListFilter) ([]sdk.Knowledge, int64, error)
+	GetKnowledge(ctx context.Context, knowledgeID string) (*sdk.Knowledge, error)
+	OpenKnowledgeFile(ctx context.Context, knowledgeID string) (string, io.ReadCloser, error)
+	HybridSearch(
+		ctx context.Context,
+		kbID string,
+		params *sdk.SearchParams,
+		opts ...sdk.ResourceURLOptions,
+	) ([]*sdk.SearchResult, error)
+}
+
+type chatService interface {
+	CreateSession(ctx context.Context, req *sdk.CreateSessionRequest) (*sdk.Session, error)
+	KnowledgeQAStream(ctx context.Context, sessionID string, req *sdk.KnowledgeQARequest, cb func(*sdk.StreamResponse) error, opts ...sdk.ResourceURLOptions) error
+}
+
+type agentService interface {
+	ListAgents(ctx context.Context) ([]sdk.Agent, error)
+	GetAgent(ctx context.Context, agentID string) (*sdk.Agent, error)
+	AgentQAStreamWithRequest(ctx context.Context, sessionID string, req *sdk.AgentQARequest, cb sdk.AgentEventCallback, opts ...sdk.ResourceURLOptions) error
+}
+
+// chunkListService is the narrow surface chunk_list depends on. Kept
+// separate from knowledgeService because the chunk subtree is its own
+// domain on the server side (/api/v1/chunks/...).
+type chunkListService interface {
+	ListKnowledgeChunks(ctx context.Context, knowledgeID string, page, pageSize int, chunkTypes ...string) ([]sdk.Chunk, int64, error)
+}
+
+// sessionAskService composes the two SDK methods session_ask needs
+// (CreateSession for the auto-session path + AgentQAStreamWithRequest
+// for the run itself). Declared here alongside the per-domain
+// interfaces above so ServiceClient (server.go) - which embeds the
+// four domain interfaces - also satisfies it.
+type sessionAskService interface {
+	CreateSession(ctx context.Context, req *sdk.CreateSessionRequest) (*sdk.Session, error)
+	AgentQAStreamWithRequest(ctx context.Context, sessionID string, req *sdk.AgentQARequest, cb sdk.AgentEventCallback, opts ...sdk.ResourceURLOptions) error
+}
+
+// registerTools wires the curated 10 tools onto server. Adding a tool here
+// is a deliberate API expansion - the agent-callable surface is the
+// reason this CLI ships an MCP server, not its CLI command list, so this
+// list must be maintained by hand.
+//
+// TODO: add OutputSchema to each mcpsdk.Tool registration so agents can
+// type-check responses without structural probing. Currently omitted
+// because the Out type is `any` on all handlers (required to suppress
+// the SDK's auto-marshal which clobbers our manually-populated
+// StructuredContent). When go-sdk exposes a typed OutputSchema field
+// independent of the handler Out type, populate it from the
+// corresponding *Output struct.
+func registerTools(server *mcpsdk.Server, svc ServiceClient) {
+	addKBList(server, svc)
+	addKBView(server, svc)
+	addDocList(server, svc)
+	addDocView(server, svc)
+	addDocDownload(server, svc)
+	addSearchChunks(server, svc)
+	addChat(server, svc)
+	addAgentList(server, svc)
+	addSessionAsk(server, svc)
+	addChunkList(server, svc)
+}
+
+// ---- kb_list -------------------------------------------------------------
+
+type kbListInput struct{}
+
+type kbListOutput struct {
+	Items []sdk.KnowledgeBase `json:"items"`
+}
+
+func addKBList(server *mcpsdk.Server, svc knowledgeBaseService) {
+	mcpsdk.AddTool(server, &mcpsdk.Tool{
+		Name:        "kb_list",
+		Description: "List all knowledge bases visible to the active WeKnora tenant. No arguments. Returns items[]: each item carries id, name, description, knowledge_count, is_pinned, updated_at - useful for selecting a kb_id to pass to other tools.",
+		Annotations: &mcpsdk.ToolAnnotations{
+			Title:           "List Knowledge Bases",
+			DestructiveHint: bptr(false),
+			ReadOnlyHint:    true,
+			IdempotentHint:  true,
+			OpenWorldHint:   bptr(false),
+		},
+	}, func(ctx context.Context, _ *mcpsdk.CallToolRequest, _ kbListInput) (*mcpsdk.CallToolResult, any, error) {
+		items, err := svc.ListKnowledgeBases(ctx)
+		if err != nil {
+			return toolErrorResult(cmdutil.WrapHTTP(err, "list knowledge bases")), nil, nil
+		}
+		if items == nil {
+			items = []sdk.KnowledgeBase{}
+		}
+		return successResult(kbListOutput{Items: items}), nil, nil
+	})
+}
+
+// ---- kb_view -------------------------------------------------------------
+
+type kbViewInput struct {
+	KBID string `json:"kb_id" jsonschema:"knowledge base ID"`
+}
+
+func addKBView(server *mcpsdk.Server, svc knowledgeBaseService) {
+	mcpsdk.AddTool(server, &mcpsdk.Tool{
+		Name:        "kb_view",
+		Description: "Fetch a knowledge base by ID. Returns the full record including chunking config, embedding/summary model IDs, knowledge_count, and chunk_count.",
+		Annotations: &mcpsdk.ToolAnnotations{
+			Title:           "View Knowledge Base",
+			DestructiveHint: bptr(false),
+			ReadOnlyHint:    true,
+			IdempotentHint:  true,
+			OpenWorldHint:   bptr(false),
+		},
+	}, func(ctx context.Context, _ *mcpsdk.CallToolRequest, in kbViewInput) (*mcpsdk.CallToolResult, any, error) {
+		if in.KBID == "" {
+			return toolErrorResult(cmdutil.NewError(cmdutil.CodeKBIDRequired, "kb_id is required")), nil, nil
+		}
+		kb, err := svc.GetKnowledgeBase(ctx, in.KBID)
+		if err != nil {
+			return toolErrorResult(cmdutil.WrapHTTP(err, "get knowledge base")), nil, nil
+		}
+		return successResult(kb), nil, nil
+	})
+}
+
+// ---- doc_list ------------------------------------------------------------
+
+type docListInput struct {
+	KBID      string `json:"kb_id" jsonschema:"knowledge base ID"`
+	Page      int    `json:"page,omitempty" jsonschema:"1-indexed page number; defaults to 1"`
+	PageSize  int    `json:"page_size,omitempty" jsonschema:"items per page (1..1000); defaults to 20"`
+	Status    string `json:"status,omitempty" jsonschema:"filter by parse status: pending | processing | completed | failed"`
+	Keyword   string `json:"keyword,omitempty" jsonschema:"server-side substring filter (case-sensitive LIKE against title / file_name); leave empty to skip"`
+	FileType  string `json:"file_type,omitempty" jsonschema:"filter by file extension (e.g. pdf, md)"`
+	Source    string `json:"source,omitempty" jsonschema:"filter by ingestion source (e.g. api, web)"`
+	TagID     string `json:"tag_id,omitempty" jsonschema:"filter by tag association"`
+	StartTime string `json:"start_time,omitempty" jsonschema:"include docs with updated_at >= this RFC3339 timestamp (e.g. 2006-01-02T15:04:05Z)"`
+	EndTime   string `json:"end_time,omitempty" jsonschema:"include docs with updated_at <= this RFC3339 timestamp (e.g. 2006-01-02T15:04:05Z)"`
+}
+
+type docListOutput struct {
+	Items    []sdk.Knowledge `json:"items"`
+	Page     int             `json:"page"`
+	PageSize int             `json:"page_size"`
+	Total    int64           `json:"total"`
+}
+
+func addDocList(server *mcpsdk.Server, svc knowledgeService) {
+	mcpsdk.AddTool(server, &mcpsdk.Tool{
+		Name:        "doc_list",
+		Description: "List documents in a knowledge base, with pagination and optional filters (parse-status, keyword, file_type, source, tag_id, start_time/end_time on updated_at). Returns items[] with id, file_name, title, parse_status, size, updated_at - plus the page/total metadata.",
+		Annotations: &mcpsdk.ToolAnnotations{
+			Title:           "List Documents",
+			DestructiveHint: bptr(false),
+			ReadOnlyHint:    true,
+			IdempotentHint:  true,
+			OpenWorldHint:   bptr(false),
+		},
+	}, func(ctx context.Context, _ *mcpsdk.CallToolRequest, in docListInput) (*mcpsdk.CallToolResult, any, error) {
+		if in.KBID == "" {
+			return toolErrorResult(cmdutil.NewError(cmdutil.CodeKBIDRequired, "kb_id is required")), nil, nil
+		}
+		page := in.Page
+		if page < 1 {
+			page = 1
+		}
+		size := in.PageSize
+		if size < 1 {
+			size = 20
+		}
+		if size > 1000 {
+			return toolErrorResult(cmdutil.NewError(cmdutil.CodeInputInvalidArgument, "page_size must be in 1..1000")), nil, nil
+		}
+		filter := sdk.KnowledgeListFilter{
+			ParseStatus: in.Status,
+			Keyword:     in.Keyword,
+			FileType:    in.FileType,
+			Source:      in.Source,
+			TagID:       in.TagID,
+		}
+		if in.StartTime != "" {
+			t, err := time.Parse(time.RFC3339, in.StartTime)
+			if err != nil {
+				return toolErrorResult(cmdutil.NewError(cmdutil.CodeInputInvalidArgument, fmt.Sprintf("start_time must be RFC3339 (e.g. 2006-01-02T15:04:05Z), got %q", in.StartTime))), nil, nil
+			}
+			filter.StartTime = t
+		}
+		if in.EndTime != "" {
+			t, err := time.Parse(time.RFC3339, in.EndTime)
+			if err != nil {
+				return toolErrorResult(cmdutil.NewError(cmdutil.CodeInputInvalidArgument, fmt.Sprintf("end_time must be RFC3339 (e.g. 2006-01-02T15:04:05Z), got %q", in.EndTime))), nil, nil
+			}
+			filter.EndTime = t
+		}
+		items, total, err := svc.ListKnowledgeWithFilter(ctx, in.KBID, page, size, filter)
+		if err != nil {
+			return toolErrorResult(cmdutil.WrapHTTP(err, "list documents")), nil, nil
+		}
+		if items == nil {
+			items = []sdk.Knowledge{}
+		}
+		return successResult(docListOutput{Items: items, Page: page, PageSize: size, Total: total}), nil, nil
+	})
+}
+
+// ---- doc_view ------------------------------------------------------------
+
+type docViewInput struct {
+	DocID string `json:"doc_id" jsonschema:"document ID (same value as the doc-id positional in CLI commands)"`
+}
+
+func addDocView(server *mcpsdk.Server, svc knowledgeService) {
+	mcpsdk.AddTool(server, &mcpsdk.Tool{
+		Name:        "doc_view",
+		Description: "Fetch a single document by ID. Returns the Knowledge record (file_name, title, type, parse_status, size, embedding_model_id, source URL if any, etc.).",
+		Annotations: &mcpsdk.ToolAnnotations{
+			Title:           "View Document",
+			DestructiveHint: bptr(false),
+			ReadOnlyHint:    true,
+			IdempotentHint:  true,
+			OpenWorldHint:   bptr(false),
+		},
+	}, func(ctx context.Context, _ *mcpsdk.CallToolRequest, in docViewInput) (*mcpsdk.CallToolResult, any, error) {
+		if in.DocID == "" {
+			return toolErrorResult(cmdutil.NewError(cmdutil.CodeInputMissingFlag, "doc_id is required")), nil, nil
+		}
+		k, err := svc.GetKnowledge(ctx, in.DocID)
+		if err != nil {
+			return toolErrorResult(cmdutil.WrapHTTP(err, "get knowledge")), nil, nil
+		}
+		return successResult(k), nil, nil
+	})
+}
+
+// ---- doc_download --------------------------------------------------------
+
+type docDownloadInput struct {
+	DocID string `json:"doc_id" jsonschema:"document ID (same value as the doc-id positional in CLI commands)"`
+}
+
+type docDownloadOutput struct {
+	DocID    string `json:"doc_id"`
+	FileName string `json:"file_name"`
+	Bytes    int    `json:"bytes"`
+	// Content is the file contents (UTF-8 if text, base64 if the SDK
+	// reports a binary-looking blob). For binary, agents should decode
+	// before consuming.
+	Content  string `json:"content"`
+	IsBase64 bool   `json:"is_base64"`
+}
+
+// maxDocDownloadBytes caps the per-call payload to keep an agent's context
+// window safe; agents needing larger documents should chunk via doc_view +
+// search_chunks. 1 MiB matches a typical LLM context-window budget for
+// inline content (~250k tokens) while remaining cheap to serialize.
+const maxDocDownloadBytes = 1 << 20
+
+func addDocDownload(server *mcpsdk.Server, svc knowledgeService) {
+	mcpsdk.AddTool(server, &mcpsdk.Tool{
+		Name:        "doc_download",
+		Description: "Download a document's raw bytes by ID. Capped at 1 MiB per call - for larger documents, use search_chunks to find the relevant excerpts. is_base64 reports whether content was base64-encoded (heuristic: presence of NUL byte in the first 512 bytes).",
+		Annotations: &mcpsdk.ToolAnnotations{
+			Title:           "Download Document",
+			DestructiveHint: bptr(false),
+			ReadOnlyHint:    true,
+			IdempotentHint:  true,
+			OpenWorldHint:   bptr(false),
+		},
+	}, func(ctx context.Context, _ *mcpsdk.CallToolRequest, in docDownloadInput) (*mcpsdk.CallToolResult, any, error) {
+		if in.DocID == "" {
+			return toolErrorResult(cmdutil.NewError(cmdutil.CodeInputMissingFlag, "doc_id is required")), nil, nil
+		}
+		name, body, err := svc.OpenKnowledgeFile(ctx, in.DocID)
+		if err != nil {
+			return toolErrorResult(cmdutil.WrapHTTP(err, "open knowledge file")), nil, nil
+		}
+		defer body.Close()
+		buf, err := io.ReadAll(io.LimitReader(body, maxDocDownloadBytes+1))
+		if err != nil {
+			return toolErrorResult(cmdutil.Wrapf(cmdutil.CodeLocalFileIO, err, "read knowledge file")), nil, nil
+		}
+		if len(buf) > maxDocDownloadBytes {
+			return toolErrorResult(cmdutil.NewError(cmdutil.CodeInputInvalidArgument, fmt.Sprintf("document exceeds the %d-byte per-call cap; use search_chunks for excerpts", maxDocDownloadBytes))), nil, nil
+		}
+		content, isBase64 := encodeDownload(buf)
+		return successResult(docDownloadOutput{
+			DocID:    in.DocID,
+			FileName: name,
+			Bytes:    len(buf),
+			Content:  content,
+			IsBase64: isBase64,
+		}), nil, nil
+	})
+}
+
+// ---- search_chunks -------------------------------------------------------
+
+type searchChunksInput struct {
+	KBID             string  `json:"kb_id" jsonschema:"knowledge base ID to search"`
+	Query            string  `json:"query" jsonschema:"natural-language search query"`
+	Limit            int     `json:"limit,omitempty" jsonschema:"client-side cap on results (1..1000); defaults to 10"`
+	VectorThreshold  float64 `json:"vector_threshold,omitempty" jsonschema:"minimum vector similarity (0..1)"`
+	KeywordThreshold float64 `json:"keyword_threshold,omitempty" jsonschema:"minimum keyword score (0..1)"`
+}
+
+type searchChunksOutput struct {
+	Results []*sdk.SearchResult `json:"results"`
+}
+
+func addSearchChunks(server *mcpsdk.Server, svc knowledgeService) {
+	// Out = any: SDK output schema would derive from searchChunksOutput,
+	// which embeds *sdk.SearchResult - and SearchResult.Metadata is a
+	// nilable map[string]any that violates the auto-generated
+	// type=object constraint when empty. Skipping derivation by using
+	// `any` keeps the structured JSON shape identical while bypassing
+	// the over-eager validator. Same pattern applied to chat / session_ask
+	// below.
+	mcpsdk.AddTool(server, &mcpsdk.Tool{
+		Name:        "search_chunks",
+		Description: "Hybrid (vector + keyword) retrieval against a knowledge base. Returns the top chunks ranked by RRF; use this before chat to ground an answer in cited context. Results include knowledge_id, content, score - feed back into chat as context or display directly.",
+		Annotations: &mcpsdk.ToolAnnotations{
+			Title:           "Search Knowledge Chunks",
+			DestructiveHint: bptr(false),
+			ReadOnlyHint:    true,
+			IdempotentHint:  true,
+			OpenWorldHint:   bptr(false),
+		},
+	}, func(ctx context.Context, _ *mcpsdk.CallToolRequest, in searchChunksInput) (*mcpsdk.CallToolResult, any, error) {
+		if in.KBID == "" {
+			return toolErrorResult(cmdutil.NewError(cmdutil.CodeKBIDRequired, "kb_id is required")), nil, nil
+		}
+		if strings.TrimSpace(in.Query) == "" {
+			return toolErrorResult(cmdutil.NewError(cmdutil.CodeInputMissingFlag, "query cannot be empty")), nil, nil
+		}
+		limit := in.Limit
+		if limit < 1 {
+			limit = 10
+		}
+		if limit > 1000 {
+			return toolErrorResult(cmdutil.NewError(cmdutil.CodeInputInvalidArgument, "limit must be in 1..1000")), nil, nil
+		}
+		results, err := svc.HybridSearch(ctx, in.KBID, &sdk.SearchParams{
+			QueryText:        in.Query,
+			MatchCount:       limit,
+			VectorThreshold:  in.VectorThreshold,
+			KeywordThreshold: in.KeywordThreshold,
+		})
+		if err != nil {
+			return toolErrorResult(cmdutil.WrapHTTP(err, "hybrid search")), nil, nil
+		}
+		if len(results) > limit {
+			results = results[:limit]
+		}
+		if results == nil {
+			results = []*sdk.SearchResult{}
+		}
+		return successResult(searchChunksOutput{Results: results}), nil, nil
+	})
+}
+
+// ---- chat ----------------------------------------------------------------
+
+type chatInput struct {
+	KBID      string `json:"kb_id" jsonschema:"knowledge base ID to chat against"`
+	Query     string `json:"query" jsonschema:"user query"`
+	SessionID string `json:"session_id,omitempty" jsonschema:"existing session to continue; auto-created when empty"`
+	Reference bool   `json:"reference,omitempty" jsonschema:"include indexed references"`
+	Verbose   bool   `json:"verbose,omitempty" jsonschema:"include reasoning, tools, and lifecycle events"`
+}
+
+type chatOutput struct {
+	Events             []sse.ProjectedEvent `json:"events"`
+	SessionID          string               `json:"session_id"`
+	AssistantMessageID string               `json:"assistant_message_id,omitempty"`
+	KBID               string               `json:"kb_id"`
+	Query              string               `json:"query"`
+}
+
+func addChat(server *mcpsdk.Server, svc chatService) {
+	mcpsdk.AddTool(server, &mcpsdk.Tool{
+		Name:        "chat",
+		Description: "Run a RAG answer against a knowledge base. Returns a bounded answer-event projection by default; reference=true adds indexed citations and verbose=true adds reasoning, tool, and lifecycle events. MCP tools/call is buffered rather than streaming. Pass session_id to continue a conversation.",
+		Annotations: &mcpsdk.ToolAnnotations{
+			Title:           "Chat with KB (Streaming RAG)",
+			DestructiveHint: bptr(false),
+			ReadOnlyHint:    false,
+			IdempotentHint:  false,
+			OpenWorldHint:   bptr(true),
+		},
+	}, func(ctx context.Context, _ *mcpsdk.CallToolRequest, in chatInput) (*mcpsdk.CallToolResult, any, error) {
+		if in.KBID == "" {
+			return toolErrorResult(cmdutil.NewError(cmdutil.CodeKBIDRequired, "kb_id is required")), nil, nil
+		}
+		if strings.TrimSpace(in.Query) == "" {
+			return toolErrorResult(cmdutil.NewError(cmdutil.CodeInputMissingFlag, "query cannot be empty")), nil, nil
+		}
+		sessionID := in.SessionID
+		if sessionID == "" {
+			sess, err := svc.CreateSession(ctx, &sdk.CreateSessionRequest{Title: "weknora mcp chat"})
+			if err != nil {
+				return toolErrorResult(cmdutil.WrapHTTP(err, "create chat session")), nil, nil
+			}
+			sessionID = sess.ID
+		}
+		req := &sdk.KnowledgeQARequest{
+			Query:            in.Query,
+			KnowledgeBaseIDs: []string{in.KBID},
+			AgentEnabled:     false,
+			Channel:          "api",
+		}
+		projector := sse.NewProjector(in.Verbose, in.Reference, in.KBID)
+		events := make([]sse.ProjectedEvent, 0)
+		streamErr := svc.KnowledgeQAStream(ctx, sessionID, req, func(r *sdk.StreamResponse) error {
+			if event, include := projector.Chat(r); include {
+				events = append(events, event)
+			}
+			return nil
+		})
+		if streamErr != nil {
+			return toolStreamError(cmdutil.WrapStream(streamErr, "knowledge qa stream"), sessionID, projector.AssistantMessageID()), nil, nil
+		}
+		if !projector.Done() {
+			return toolStreamError(cmdutil.NewError(cmdutil.CodeSSEStreamAborted, "stream ended without a terminal event"), sessionID, projector.AssistantMessageID()), nil, nil
+		}
+		sid := projector.SessionID()
+		if sid == "" {
+			sid = sessionID
+		}
+		return successResult(chatOutput{
+			Events:             events,
+			SessionID:          sid,
+			AssistantMessageID: projector.AssistantMessageID(),
+			KBID:               in.KBID,
+			Query:              in.Query,
+		}), nil, nil
+	})
+}
+
+// ---- agent_list ----------------------------------------------------------
+
+type agentListInput struct{}
+
+type agentListOutput struct {
+	Items []sdk.Agent `json:"items"`
+}
+
+func addAgentList(server *mcpsdk.Server, svc agentService) {
+	mcpsdk.AddTool(server, &mcpsdk.Tool{
+		Name:        "agent_list",
+		Description: "List the tenant's custom agents. Returns items[] with id, name, description, is_builtin - use to discover an agent_id before session_ask.",
+		Annotations: &mcpsdk.ToolAnnotations{
+			Title:           "List Custom Agents",
+			DestructiveHint: bptr(false),
+			ReadOnlyHint:    true,
+			IdempotentHint:  true,
+			OpenWorldHint:   bptr(false),
+		},
+	}, func(ctx context.Context, _ *mcpsdk.CallToolRequest, _ agentListInput) (*mcpsdk.CallToolResult, any, error) {
+		items, err := svc.ListAgents(ctx)
+		if err != nil {
+			return toolErrorResult(cmdutil.WrapHTTP(err, "list agents")), nil, nil
+		}
+		if items == nil {
+			items = []sdk.Agent{}
+		}
+		return successResult(agentListOutput{Items: items}), nil, nil
+	})
+}
+
+// ---- session_ask ---------------------------------------------------------
+
+type sessionAskInput struct {
+	AgentID   string `json:"agent_id" jsonschema:"custom agent ID"`
+	Query     string `json:"query" jsonschema:"user query"`
+	SessionID string `json:"session_id,omitempty" jsonschema:"existing session to continue; auto-created when empty"`
+	Reference bool   `json:"reference,omitempty" jsonschema:"include indexed references"`
+	Verbose   bool   `json:"verbose,omitempty" jsonschema:"include reasoning, tools, and lifecycle events"`
+}
+
+type sessionAskOutput struct {
+	Events    []sse.ProjectedEvent `json:"events"`
+	SessionID string               `json:"session_id"`
+	AgentID   string               `json:"agent_id"`
+	Query     string               `json:"query"`
+}
+
+func addSessionAsk(server *mcpsdk.Server, svc sessionAskService) {
+	mcpsdk.AddTool(server, &mcpsdk.Tool{
+		Name:        "session_ask",
+		Description: "Run a query through a custom agent. Returns a bounded answer-event projection by default; reference=true adds indexed citations and verbose=true adds reasoning, tool, and lifecycle events. MCP tools/call is buffered rather than streaming.",
+		Annotations: &mcpsdk.ToolAnnotations{
+			Title:           "Ask a Custom Agent (session ask --agent)",
+			DestructiveHint: bptr(false),
+			ReadOnlyHint:    false,
+			IdempotentHint:  false,
+			OpenWorldHint:   bptr(true),
+		},
+	}, func(ctx context.Context, _ *mcpsdk.CallToolRequest, in sessionAskInput) (*mcpsdk.CallToolResult, any, error) {
+		if in.AgentID == "" {
+			return toolErrorResult(cmdutil.NewError(cmdutil.CodeInputMissingFlag, "agent_id is required")), nil, nil
+		}
+		if strings.TrimSpace(in.Query) == "" {
+			return toolErrorResult(cmdutil.NewError(cmdutil.CodeInputMissingFlag, "query cannot be empty")), nil, nil
+		}
+		projector := sse.NewProjector(in.Verbose, in.Reference, "")
+		events := make([]sse.ProjectedEvent, 0)
+		req := &sdk.AgentQARequest{
+			Query:        in.Query,
+			AgentEnabled: true,
+			AgentID:      in.AgentID,
+			Channel:      "api",
+		}
+		// Auto-create session if not supplied. Sessions are agent-
+		// agnostic at creation (verified against server source).
+		sessionID := in.SessionID
+		if sessionID == "" {
+			sess, err := svc.CreateSession(ctx, &sdk.CreateSessionRequest{Title: "weknora mcp session_ask"})
+			if err != nil {
+				return toolErrorResult(cmdutil.WrapHTTP(err, "create chat session")), nil, nil
+			}
+			sessionID = sess.ID
+		}
+		streamErr := svc.AgentQAStreamWithRequest(ctx, sessionID, req, func(r *sdk.AgentStreamResponse) error {
+			if event, include := projector.Agent(r); include {
+				events = append(events, event)
+			}
+			return nil
+		})
+		if streamErr != nil {
+			return toolStreamError(cmdutil.WrapStream(streamErr, "agent-chat stream"), sessionID, ""), nil, nil
+		}
+		if !projector.Done() {
+			return toolStreamError(cmdutil.NewError(cmdutil.CodeSSEStreamAborted, "stream ended without a terminal event"), sessionID, ""), nil, nil
+		}
+		return successResult(sessionAskOutput{
+			Events:    events,
+			SessionID: sessionID,
+			AgentID:   in.AgentID,
+			Query:     in.Query,
+		}), nil, nil
+	})
+}
+
+// ---- chunk_list ----------------------------------------------------------
+
+type chunkListInput struct {
+	DocID string `json:"doc_id" jsonschema:"document (knowledge entry) ID"`
+	Limit int    `json:"limit,omitempty" jsonschema:"max chunks to return (1..1000); defaults to 50"`
+}
+
+type chunkListOutput struct {
+	Chunks           []sdk.Chunk `json:"chunks"`
+	Total            int64       `json:"total"`
+	TruncatedAtLimit bool        `json:"truncated_at_limit"`
+}
+
+// chunkListDefaultLimit + chunkListMaxLimit mirror the schema's default+max.
+// MCP schema deliberately exposes only `limit`, not the CLI's full
+// --limit/--page/--page-size triple: LLM agents typically need a single
+// bounded fetch, not pagination workflows. Above 1000, fall back to the CLI.
+const (
+	chunkListDefaultLimit = 50
+	chunkListMaxLimit     = 1000
+)
+
+func addChunkList(server *mcpsdk.Server, svc chunkListService) {
+	mcpsdk.AddTool(server, &mcpsdk.Tool{
+		Name:        "chunk_list",
+		Description: "List chunks of a knowledge document for RAG retrieval debug. Returns at most `limit` chunks starting from ChunkIndex 0; if total chunks exceed limit, truncated_at_limit=true signals the agent to fall back to the CLI for paginated retrieval.",
+		Annotations: &mcpsdk.ToolAnnotations{
+			Title:           "List Knowledge Chunks",
+			DestructiveHint: bptr(false),
+			ReadOnlyHint:    true,
+			IdempotentHint:  true,
+			OpenWorldHint:   bptr(false),
+		},
+	}, func(ctx context.Context, _ *mcpsdk.CallToolRequest, in chunkListInput) (*mcpsdk.CallToolResult, any, error) {
+		if in.DocID == "" {
+			return toolErrorResult(cmdutil.NewError(cmdutil.CodeInputMissingFlag, "doc_id is required")), nil, nil
+		}
+		// `limit` is typed as int by chunkListInput, so the SDK rejects
+		// non-numeric values at schema validation (e.g. "limit":"50")
+		// before this handler runs. Default when unset; reject over-max
+		// (rather than silently clamping) so the agent's request is never
+		// quietly changed — matching search_chunks in this same file.
+		limit := in.Limit
+		if limit < 1 {
+			limit = chunkListDefaultLimit
+		}
+		if limit > chunkListMaxLimit {
+			return toolErrorResult(cmdutil.NewError(cmdutil.CodeInputInvalidArgument, fmt.Sprintf("limit must be in 1..%d", chunkListMaxLimit))), nil, nil
+		}
+		chunks, total, err := svc.ListKnowledgeChunks(ctx, in.DocID, 1, limit)
+		if err != nil {
+			return toolErrorResult(cmdutil.WrapHTTP(err, "list knowledge chunks")), nil, nil
+		}
+		if chunks == nil {
+			chunks = []sdk.Chunk{}
+		}
+		return successResult(chunkListOutput{
+			Chunks:           chunks,
+			Total:            total,
+			TruncatedAtLimit: total > int64(limit),
+		}), nil, nil
+	})
+}
+
+// encodeDownload returns (content, isBase64). Heuristic: if the first 512
+// bytes contain a NUL, treat as binary. Otherwise it's UTF-8-ish text.
+// Matches what /usr/bin/file's "binary" heuristic does at a coarse level -
+// good enough to spare an agent from base64-decoding obvious text.
+func encodeDownload(buf []byte) (string, bool) {
+	probe := buf
+	if len(probe) > 512 {
+		probe = probe[:512]
+	}
+	for _, b := range probe {
+		if b == 0 {
+			return base64.StdEncoding.EncodeToString(buf), true
+		}
+	}
+	return string(buf), false
+}
+
+// bptr returns a pointer to a bool literal. MCP ToolAnnotations uses
+// pointer types for DestructiveHint and OpenWorldHint so that "explicit
+// false" can be distinguished from "field omitted (default true per MCP
+// spec 2025-06-18)".
+func bptr(b bool) *bool { return &b }