fix: hide disabled model-invocation skills from briefs (#5311)

Co-authored-by: Eve <eve@multica-ai.local>
Co-authored-by: multica-agent <github@multica.ai>

server/internal/daemon/execenv/context.go

@@ -668,10 +668,11 @@ func renderIssueContext(provider string, ctx TaskContextForEnv) string {
 	b.WriteString("## Quick Start\n\n")
 	fmt.Fprintf(&b, "Run `multica issue get %s --output json` to fetch the full issue details.\n\n", ctx.IssueID)
 
-	if len(ctx.AgentSkills) > 0 {
+	skills := modelVisibleSkills(ctx.AgentSkills)
+	if len(skills) > 0 {
 		b.WriteString("## Agent Skills\n\n")
 		b.WriteString("The following skills are available to you:\n\n")
-		for _, skill := range ctx.AgentSkills {
+		for _, skill := range skills {
 			fmt.Fprintf(&b, "- **%s**\n", skill.Name)
 		}
 		b.WriteString("\n")
@@ -692,9 +693,10 @@ func renderQuickCreateContext(ctx TaskContextForEnv) string {
 	b.WriteString("> ")
 	b.WriteString(ctx.QuickCreatePrompt)
 	b.WriteString("\n\n")
-	if len(ctx.AgentSkills) > 0 {
+	skills := modelVisibleSkills(ctx.AgentSkills)
+	if len(skills) > 0 {
 		b.WriteString("## Agent Skills\n\n")
-		for _, skill := range ctx.AgentSkills {
+		for _, skill := range skills {
 			fmt.Fprintf(&b, "- **%s**\n", skill.Name)
 		}
 		b.WriteString("\n")
@@ -731,10 +733,11 @@ func renderAutopilotContext(ctx TaskContextForEnv) string {
 		b.WriteString("\n\n")
 	}
 
-	if len(ctx.AgentSkills) > 0 {
+	skills := modelVisibleSkills(ctx.AgentSkills)
+	if len(skills) > 0 {
 		b.WriteString("## Agent Skills\n\n")
 		b.WriteString("The following skills are available to you:\n\n")
-		for _, skill := range ctx.AgentSkills {
+		for _, skill := range skills {
 			fmt.Fprintf(&b, "- **%s**\n", skill.Name)
 		}
 		b.WriteString("\n")

server/internal/daemon/execenv/runtime_config_sections.go

@@ -421,7 +421,8 @@ func writeSubIssueCreation(b *strings.Builder) {
 
 // writeSkills emits the Skills section listing skill names + descriptions.
 func writeSkills(b *strings.Builder, provider string, ctx TaskContextForEnv) {
-	if len(ctx.AgentSkills) == 0 {
+	skills := modelVisibleSkills(ctx.AgentSkills)
+	if len(skills) == 0 {
 		return
 	}
 	b.WriteString("## Skills\n\n")
@@ -435,7 +436,7 @@ func writeSkills(b *strings.Builder, provider string, ctx TaskContextForEnv) {
 	default:
 		b.WriteString("Detailed skill instructions are in `.agent_context/skills/`. Each subdirectory contains a `SKILL.md`.\n\n")
 	}
-	for _, skill := range ctx.AgentSkills {
+	for _, skill := range skills {
 		if desc := strings.TrimSpace(skill.Description); desc != "" {
 			fmt.Fprintf(b, "- **%s** — %s\n", skill.Name, desc)
 		} else {

server/internal/daemon/execenv/skill_visibility.go

@@ -0,0 +1,47 @@
+package execenv
+
+import (
+	"strings"
+
+	"gopkg.in/yaml.v3"
+)
+
+func modelVisibleSkills(skills []SkillContextForEnv) []SkillContextForEnv {
+	if len(skills) == 0 {
+		return nil
+	}
+	visible := make([]SkillContextForEnv, 0, len(skills))
+	for _, skill := range skills {
+		if skillModelInvocationVisible(skill) {
+			visible = append(visible, skill)
+		}
+	}
+	return visible
+}
+
+func skillModelInvocationVisible(skill SkillContextForEnv) bool {
+	return !skillDisablesModelInvocation(skill.Content)
+}
+
+func skillDisablesModelInvocation(content string) bool {
+	fmBody, _, ok := frontmatterParts(content)
+	if !ok || strings.TrimSpace(fmBody) == "" {
+		return false
+	}
+	var data map[string]any
+	if err := yaml.Unmarshal([]byte(fmBody), &data); err != nil {
+		return false
+	}
+	value, ok := data["disable-model-invocation"]
+	if !ok {
+		return false
+	}
+	switch v := value.(type) {
+	case bool:
+		return v
+	case string:
+		return strings.EqualFold(strings.TrimSpace(v), "true")
+	default:
+		return false
+	}
+}

server/internal/daemon/execenv/skill_visibility_test.go

@@ -0,0 +1,226 @@
+package execenv
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestSkillModelInvocationVisibility(t *testing.T) {
+	t.Parallel()
+
+	cases := []struct {
+		name    string
+		content string
+		want    bool
+	}{
+		{
+			name:    "no frontmatter is visible",
+			content: "body",
+			want:    true,
+		},
+		{
+			name: "disable true is hidden",
+			content: `---
+name: hidden
+disable-model-invocation: true
+---
+
+body`,
+			want: false,
+		},
+		{
+			name: "disable quoted true is hidden",
+			content: `---
+name: hidden
+disable-model-invocation: "true"
+---
+
+body`,
+			want: false,
+		},
+		{
+			name: "disable false is visible",
+			content: `---
+name: visible
+disable-model-invocation: false
+---
+
+body`,
+			want: true,
+		},
+		{
+			name: "user invocable false is still visible",
+			content: `---
+name: visible
+user-invocable: false
+---
+
+body`,
+			want: true,
+		},
+		{
+			name: "invalid frontmatter is visible",
+			content: `---
+name: visible
+description: bad: value
+disable-model-invocation: true
+---
+
+body`,
+			want: true,
+		},
+	}
+
+	for _, tc := range cases {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+			got := skillModelInvocationVisible(SkillContextForEnv{Content: tc.content})
+			if got != tc.want {
+				t.Errorf("skillModelInvocationVisible = %v, want %v", got, tc.want)
+			}
+		})
+	}
+}
+
+func TestRenderedSkillListsHideDisableModelInvocationSkills(t *testing.T) {
+	t.Parallel()
+
+	ctx := TaskContextForEnv{
+		IssueID:           "issue-1",
+		QuickCreatePrompt: "create something",
+		AutopilotRunID:    "run-1",
+		AgentName:         "Eve",
+		AgentID:           "eve-1",
+		AgentSkills: []SkillContextForEnv{
+			{
+				Name:        "Visible Skill",
+				Description: "visible description",
+				Content: `---
+name: visible-skill
+---
+
+Visible body.`,
+			},
+			{
+				Name:        "Hidden Skill",
+				Description: "hidden description",
+				Content: `---
+name: hidden-skill
+disable-model-invocation: true
+---
+
+Hidden body.`,
+			},
+		},
+	}
+
+	rendered := map[string]string{
+		"runtime config": buildMetaSkillContent("codex", TaskContextForEnv{
+			IssueID:     ctx.IssueID,
+			AgentName:   ctx.AgentName,
+			AgentID:     ctx.AgentID,
+			AgentSkills: ctx.AgentSkills,
+		}),
+		"issue context": renderIssueContext("codex", TaskContextForEnv{
+			IssueID:     ctx.IssueID,
+			AgentSkills: ctx.AgentSkills,
+		}),
+		"quick create": renderQuickCreateContext(TaskContextForEnv{
+			QuickCreatePrompt: ctx.QuickCreatePrompt,
+			AgentSkills:       ctx.AgentSkills,
+		}),
+		"autopilot": renderAutopilotContext(TaskContextForEnv{
+			AutopilotRunID: ctx.AutopilotRunID,
+			AgentSkills:    ctx.AgentSkills,
+		}),
+	}
+
+	for name, out := range rendered {
+		if !strings.Contains(out, "Visible Skill") {
+			t.Errorf("%s missing visible skill:\n%s", name, out)
+		}
+		if strings.Contains(out, "Hidden Skill") || strings.Contains(out, "hidden description") {
+			t.Errorf("%s advertised disable-model-invocation skill:\n%s", name, out)
+		}
+	}
+}
+
+func TestRenderedSkillListsOmitSectionWhenOnlyDisabledSkills(t *testing.T) {
+	t.Parallel()
+
+	ctx := TaskContextForEnv{
+		IssueID: "issue-1",
+		AgentSkills: []SkillContextForEnv{
+			{
+				Name: "Hidden Skill",
+				Content: `---
+name: hidden-skill
+disable-model-invocation: true
+---
+
+Hidden body.`,
+			},
+		},
+	}
+
+	runtimeConfig := buildMetaSkillContent("codex", ctx)
+	if strings.Contains(runtimeConfig, "## Skills") {
+		t.Errorf("runtime config should omit Skills section when every skill disables model invocation:\n%s", runtimeConfig)
+	}
+
+	issueContext := renderIssueContext("codex", ctx)
+	if strings.Contains(issueContext, "## Agent Skills") {
+		t.Errorf("issue context should omit Agent Skills section when every skill disables model invocation:\n%s", issueContext)
+	}
+}
+
+func TestWriteContextFilesHydratesDisableModelInvocationSkillButDoesNotAdvertiseIt(t *testing.T) {
+	t.Parallel()
+
+	dir := t.TempDir()
+	ctx := TaskContextForEnv{
+		IssueID: "issue-1",
+		AgentSkills: []SkillContextForEnv{
+			{
+				Name: "Visible Skill",
+				Content: `---
+name: visible-skill
+---
+
+Visible body.`,
+			},
+			{
+				Name: "Hidden Skill",
+				Content: `---
+name: hidden-skill
+disable-model-invocation: true
+---
+
+Hidden body.`,
+			},
+		},
+	}
+
+	if err := writeContextFiles(dir, "", ctx, nil); err != nil {
+		t.Fatalf("writeContextFiles failed: %v", err)
+	}
+
+	issueContext, err := os.ReadFile(filepath.Join(dir, ".agent_context", "issue_context.md"))
+	if err != nil {
+		t.Fatalf("read issue_context.md: %v", err)
+	}
+	if strings.Contains(string(issueContext), "Hidden Skill") {
+		t.Fatalf("issue_context.md advertised hidden skill:\n%s", string(issueContext))
+	}
+
+	hiddenSkill, err := os.ReadFile(filepath.Join(dir, ".agent_context", "skills", "hidden-skill", "SKILL.md"))
+	if err != nil {
+		t.Fatalf("disabled skill should still be hydrated on disk: %v", err)
+	}
+	if !strings.Contains(string(hiddenSkill), "disable-model-invocation: true") {
+		t.Errorf("hidden skill frontmatter should be preserved on disk:\n%s", string(hiddenSkill))
+	}
+}