diff --git a/internal/app/mcp_authorization.go b/internal/app/mcp_authorization.go
index cd933a79..6526de7d 100644
--- a/internal/app/mcp_authorization.go
+++ b/internal/app/mcp_authorization.go
@@ -382,7 +382,13 @@ func authorizeProjectTool(ctx context.Context, principal authctx.Principal, db *
 		return fmt.Errorf("no access to conversation %s", conversationID)
 	}
 	projectID, err := db.GetConversationProjectID(conversationID)
-	if err != nil || strings.TrimSpace(projectID) == "" || !db.UserCanAccessResource(principal.UserID, principal.ScopeFor(permission), "project", projectID) {
+	if err != nil {
+		return fmt.Errorf("no access to project: %w", err)
+	}
+	if strings.TrimSpace(projectID) == "" {
+		return fmt.Errorf("当前对话未绑定项目，无法使用项目黑板工具，请先在对话中选择项目或创建带项目的对话")
+	}
+	if !db.UserCanAccessResource(principal.UserID, principal.ScopeFor(permission), "project", projectID) {
 		return fmt.Errorf("no access to project %s", projectID)
 	}
 	return nil
diff --git a/internal/database/project.go b/internal/database/project.go
index df2604eb..c2201267 100644
--- a/internal/database/project.go
+++ b/internal/database/project.go
@@ -10,7 +10,7 @@ import (
 	"github.com/google/uuid"
 )
 
-var factKeyPattern = regexp.MustCompile(`^[a-z0-9][a-z0-9._/-]*$`)
+var factKeyPattern = regexp.MustCompile(`^[a-zA-Z0-9][a-zA-Z0-9._/-]*$`)
 
 // ValidateFactKey 校验事实 key（项目内唯一标识）。
 func ValidateFactKey(key string) error {
@@ -22,7 +22,7 @@ func ValidateFactKey(key string) error {
 		return fmt.Errorf("fact_key 过长（最多 128 字符）")
 	}
 	if !factKeyPattern.MatchString(key) {
-		return fmt.Errorf("fact_key 格式无效，仅允许小写字母、数字及 . _ / -，且须以小写字母或数字开头")
+		return fmt.Errorf("fact_key 格式无效，仅允许字母、数字及 . _ / -，且须以字母或数字开头（支持驼峰命名）")
 	}
 	return nil
 }
diff --git a/internal/project/fact_body_links.go b/internal/project/fact_body_links.go
index 0ec69328..8c0bd39c 100644
--- a/internal/project/fact_body_links.go
+++ b/internal/project/fact_body_links.go
@@ -9,8 +9,8 @@ import (
 )
 
 var (
-	bodyDepFactLine   = regexp.MustCompile(`(?im)^[\s\-*]*依赖事实\s*[:：]\s*([a-z0-9][a-z0-9._/-]*)`)
-	bodyRelFactLine   = regexp.MustCompile(`(?im)^[\s\-*]*相关\s*fact_key\s*[:：]\s*([a-z0-9][a-z0-9._/-]*)`)
+	bodyDepFactLine   = regexp.MustCompile(`(?im)^[\s\-*]*依赖事实\s*[:：]\s*([a-zA-Z0-9][a-zA-Z0-9._/-]*)`)
+	bodyRelFactLine   = regexp.MustCompile(`(?im)^[\s\-*]*相关\s*fact_key\s*[:：]\s*([a-zA-Z0-9][a-zA-Z0-9._/-]*)`)
 	bodyAssocSection  = regexp.MustCompile(`(?im)^##\s*关联\s*$`)
 	bodySyncLinksHead = "结构化关系边（自动同步）"
 )