feat(skills): add support for disable model invocation

Author: taciturnaxolotl

README.md

@@ -462,6 +462,37 @@ git clone https://github.com/anthropics/skills.git _temp
 mv _temp/skills/* . ; rm -r -force _temp
 ```
 
+#### User-Invocable Skills
+
+Skills can be made invocable as commands from the commands palette (Ctrl+P). Add `user-invocable: true` to the skill's YAML frontmatter:
+
+```yaml
+---
+name: my-skill
+description: A skill that can be invoked as a command.
+user-invocable: true
+---
+```
+
+User-invocable skills appear in the commands palette with a `user:` or `project:` prefix:
+- Skills from global directories show as `user:skill-name`
+- Skills from project directories show as `project:skill-name`
+
+When invoked, the skill's instructions are loaded into the conversation context.
+
+To prevent the model from auto-triggering a skill (while still allowing user invocation), add `disable-model-invocation: true`:
+
+```yaml
+---
+name: my-skill
+description: Only invocable by users, not the model.
+user-invocable: true
+disable-model-invocation: true
+---
+```
+
+Skills with `disable-model-invocation` won't appear in the model's available skills list but can still be invoked manually by users.
+
 ### Desktop notifications
 
 Crush sends desktop notifications when a tool call requires permission and when

internal/skills/builtin/crush-config/SKILL.md

@@ -156,6 +156,37 @@ The `$schema` property enables IDE autocomplete but is optional.
 
 Other options: `context_paths`, `progress`, `disable_notifications`, `disable_auto_summarize`, `disable_metrics`, `disable_provider_auto_update`, `disable_default_providers`, `data_directory`, `initialize_as`.
 
+## User-Invocable Skills
+
+Skills can be made invocable as commands from the commands palette. Add `user-invocable: true` to the skill's YAML frontmatter:
+
+```yaml
+---
+name: my-skill
+description: A skill that can be invoked as a command.
+user-invocable: true
+---
+```
+
+User-invocable skills appear in the commands palette with a prefix:
+- Skills from global directories: `user:skill-name`
+- Skills from project directories: `project:skill-name`
+
+When invoked, the skill's instructions are loaded into the conversation context.
+
+To prevent the model from auto-triggering a skill (while still allowing user invocation), add `disable-model-invocation: true`:
+
+```yaml
+---
+name: my-skill
+description: Only invocable by users, not the model.
+user-invocable: true
+disable-model-invocation: true
+---
+```
+
+Skills with `disable-model-invocation` won't appear in the model's available skills list but can still be invoked manually by users.
+
 ## Hooks
 
 Hooks are user-defined shell commands that fire on agent events. Currently only `PreToolUse` is supported, which runs before a tool is executed.

internal/skills/skills.go

@@ -34,16 +34,17 @@ var (
 
 // Skill represents a parsed SKILL.md file.
 type Skill struct {
-	Name          string            `yaml:"name" json:"name"`
-	Description   string            `yaml:"description" json:"description"`
-	UserInvocable bool              `yaml:"user-invocable" json:"user_invocable"`
-	License       string            `yaml:"license,omitempty" json:"license,omitempty"`
-	Compatibility string            `yaml:"compatibility,omitempty" json:"compatibility,omitempty"`
-	Metadata      map[string]string `yaml:"metadata,omitempty" json:"metadata,omitempty"`
-	Instructions  string            `yaml:"-" json:"instructions"`
-	Path          string            `yaml:"-" json:"path"`
-	SkillFilePath string            `yaml:"-" json:"skill_file_path"`
-	Builtin       bool              `yaml:"-" json:"builtin"`
+	Name                  string            `yaml:"name" json:"name"`
+	Description           string            `yaml:"description" json:"description"`
+	UserInvocable         bool              `yaml:"user-invocable" json:"user_invocable"`
+	DisableModelInvocation bool             `yaml:"disable-model-invocation" json:"disable_model_invocation"`
+	License               string            `yaml:"license,omitempty" json:"license,omitempty"`
+	Compatibility         string            `yaml:"compatibility,omitempty" json:"compatibility,omitempty"`
+	Metadata              map[string]string `yaml:"metadata,omitempty" json:"metadata,omitempty"`
+	Instructions          string            `yaml:"-" json:"instructions"`
+	Path                  string            `yaml:"-" json:"path"`
+	SkillFilePath         string            `yaml:"-" json:"skill_file_path"`
+	Builtin               bool              `yaml:"-" json:"builtin"`
 }
 
 // DiscoveryState represents the outcome of discovering a single skill file.
@@ -259,6 +260,7 @@ func DiscoverWithStates(paths []string) ([]*Skill, []*SkillState) {
 }
 
 // ToPromptXML generates XML for injection into the system prompt.
+// Skills with DisableModelInvocation set to true are excluded.
 func ToPromptXML(skills []*Skill) string {
 	if len(skills) == 0 {
 		return ""
@@ -267,6 +269,10 @@ func ToPromptXML(skills []*Skill) string {
 	var sb strings.Builder
 	sb.WriteString("<available_skills>\n")
 	for _, s := range skills {
+		// Skip skills that have disable-model-invocation set
+		if s.DisableModelInvocation {
+			continue
+		}
 		sb.WriteString("  <skill>\n")
 		fmt.Fprintf(&sb, "    <name>%s</name>\n", escape(s.Name))
 		fmt.Fprintf(&sb, "    <description>%s</description>\n", escape(s.Description))

internal/skills/skills_test.go

@@ -330,6 +330,20 @@ func TestToPromptXML(t *testing.T) {
 	require.Contains(t, xml, "&") // XML escaping
 }
 
+func TestToPromptXMLDisableModelInvocation(t *testing.T) {
+	t.Parallel()
+
+	skills := []*Skill{
+		{Name: "visible-skill", Description: "This one appears.", SkillFilePath: "/skills/visible/SKILL.md"},
+		{Name: "hidden-skill", Description: "This one is hidden.", SkillFilePath: "/skills/hidden/SKILL.md", DisableModelInvocation: true},
+	}
+
+	xml := ToPromptXML(skills)
+
+	require.Contains(t, xml, "<name>visible-skill</name>")
+	require.NotContains(t, xml, "<name>hidden-skill</name>")
+}
+
 func TestToPromptXMLEmpty(t *testing.T) {
 	t.Parallel()
 	require.Empty(t, ToPromptXML(nil))