diff --git a/backend/internal/app/cloud_agent_contract_test.go b/backend/internal/app/cloud_agent_contract_test.go
index 51e22506c..dcf46105b 100644
--- a/backend/internal/app/cloud_agent_contract_test.go
+++ b/backend/internal/app/cloud_agent_contract_test.go
@@ -215,16 +215,28 @@ func TestCloudAgentAnnotationRenderFeedsControlledTransientReference(t *testing.
 }
 
 func TestCloudAgentPolicyPublishesSkillManifestWithoutInliningSkillBody(t *testing.T) {
-	skill := cloudAgentSkill{ID: "skill-1", Name: "任务技能", Version: "v1", Hash: agentProfileHash("skill"), Instruction: "PRIVATE_SKILL_BODY", Files: map[string]string{"references/a.md": "A"}}
+	skill := cloudAgentSkill{ID: "skill-1", Name: "任务技能", Description: "当用户要写短剧剧本时调用", Version: "v1", Hash: agentProfileHash("skill"), Instruction: "PRIVATE_SKILL_BODY", Files: map[string]string{"references/a.md": "A"}}
 	text, _, err := compileCloudAgentPolicies(agentTestRequest(), []cloudAgentSkill{skill}, "", cloudAgentProfileSnapshot{Revision: agentProfileRevision(nil), Hash: agentProfileHash("")})
 	if err != nil {
 		t.Fatal(err)
 	}
-	if strings.Contains(text, skill.Instruction) || !strings.Contains(text, `"entryPath":"SKILL.md"`) || !strings.Contains(text, `"files":["SKILL.md","references/a.md"]`) {
+	if strings.Contains(text, skill.Instruction) || !strings.Contains(text, `"entryPath":"SKILL.md"`) || !strings.Contains(text, `"files":["SKILL.md","references/a.md"]`) || !strings.Contains(text, `"description":"当用户要写短剧剧本时调用"`) {
 		t.Fatalf("compiled policy did not publish a safe on-demand skill manifest: %s", text)
 	}
 }
 
+func TestCloudAgentPolicyTruncatesOversizedSkillDescription(t *testing.T) {
+	long := strings.Repeat("描", 600)
+	skill := cloudAgentSkill{ID: "skill-2", Name: "长描述技能", Description: long, Version: "v1", Hash: agentProfileHash("skill2")}
+	text, _, err := compileCloudAgentPolicies(agentTestRequest(), []cloudAgentSkill{skill}, "", cloudAgentProfileSnapshot{Revision: agentProfileRevision(nil), Hash: agentProfileHash("")})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if strings.Contains(text, long) || !strings.Contains(text, strings.Repeat("描", 500)+"…") {
+		t.Fatalf("oversized skill description was not capped at 500 runes: %s", text)
+	}
+}
+
 func TestCloudAgentPolicyPublishesCapabilityRoutingGuide(t *testing.T) {
 	text, _, err := compileCloudAgentPolicies(agentTestRequest(), nil, "", cloudAgentProfileSnapshot{Revision: agentProfileRevision(nil), Hash: agentProfileHash("")})
 	if err != nil {
diff --git a/backend/internal/app/cloud_agent_policy.go b/backend/internal/app/cloud_agent_policy.go
index 7feb41f75..f89ba8729 100644
--- a/backend/internal/app/cloud_agent_policy.go
+++ b/backend/internal/app/cloud_agent_policy.go
@@ -84,6 +84,19 @@ func cloudAgentCapabilityGuide() string {
 	return b.String()
 }
 
+// cloudAgentSkillManifestDescription bounds the system prompt: the description
+// is author-supplied public metadata, so it is trimmed and capped before it
+// enters the compiled policy.
+func cloudAgentSkillManifestDescription(description string) string {
+	const maxRunes = 500
+	trimmed := strings.TrimSpace(description)
+	if utf8.RuneCountInString(trimmed) <= maxRunes {
+		return trimmed
+	}
+	runes := []rune(trimmed)
+	return strings.TrimSpace(string(runes[:maxRunes])) + "…"
+}
+
 func compileCloudAgentPolicies(req CloudAgentRequest, skills []cloudAgentSkill, canvasSummary string, profile cloudAgentProfileSnapshot, anchors ...cloudAgentCreativeAnchor) (string, cloudAgentPolicySnapshot, error) {
 	system, media, err := prompts.LoadAgentPolicies()
 	if err != nil {
@@ -121,7 +134,7 @@ func compileCloudAgentPolicies(req CloudAgentRequest, skills []cloudAgentSkill,
 	}
 	manifests := make([]map[string]any, 0, len(skills))
 	for _, skill := range skills {
-		manifests = append(manifests, map[string]any{"skillId": skill.ID, "name": skill.Name, "version": skill.Version, "hash": skill.Hash, "entryPath": cloudAgentSkillEntryPath, "files": cloudAgentSkillPaths(skill)})
+		manifests = append(manifests, map[string]any{"skillId": skill.ID, "name": skill.Name, "description": cloudAgentSkillManifestDescription(skill.Description), "version": skill.Version, "hash": skill.Hash, "entryPath": cloudAgentSkillEntryPath, "files": cloudAgentSkillPaths(skill)})
 	}
 	context["skills"] = manifests
 	layers := make([]map[string]any, 0, len(profile.Layers))
diff --git a/backend/internal/app/cloud_agent_tools.go b/backend/internal/app/cloud_agent_tools.go
index 742038745..5455c3915 100644
--- a/backend/internal/app/cloud_agent_tools.go
+++ b/backend/internal/app/cloud_agent_tools.go
@@ -22,6 +22,7 @@ import (
 type cloudAgentSkill struct {
 	ID          string            `json:"id"`
 	Name        string            `json:"name"`
+	Description string            `json:"description,omitempty"`
 	Version     string            `json:"version"`
 	Hash        string            `json:"hash"`
 	Instruction string            `json:"instruction,omitempty"`
@@ -60,7 +61,9 @@ func (s *Service) cloudAgentSkills(userID string, ids []string) ([]cloudAgentSki
 		}
 		// Skill content is loaded only after the model explicitly calls
 		// skill_read_file; keep the run context to stable metadata and paths.
-		snapshot := cloudAgentSkill{ID: id, Name: skill.SkillName, Version: skill.VersionID, Hash: skill.ContentHash, Files: map[string]string{cloudAgentSkillEntryPath: ""}}
+		// The description is public metadata (market listing) and lets the
+		// model route between activated skills without reading any body.
+		snapshot := cloudAgentSkill{ID: id, Name: skill.SkillName, Description: skill.Description, Version: skill.VersionID, Hash: skill.ContentHash, Files: map[string]string{cloudAgentSkillEntryPath: ""}}
 		files, err := s.SkillPackageFiles(userID, id)
 		if err != nil {
 			return nil, err