Struct SkillDescriptor 

pub struct SkillDescriptor {
    pub name: String,
    pub description: String,
    pub location: PathBuf,
    pub license: Option<String>,
    pub compatibility: Option<String>,
    pub metadata: HashMap<String, String>,
    pub allowed_tools: Vec<String>,
    pub shell: Option<String>,
    pub paths: Vec<String>,
    pub hooks: Option<HooksDefinition>,
}

Lightweight skill metadata loaded at discovery time (Tier 1).

Aligned with the agentskills.io specification. Only name and description are required; all other fields are optional.

At session startup the agent builds a catalog from all discovered descriptors and injects it into the system prompt. Each descriptor costs ~50-100 tokens, so even dozens of skills keep the base context small.

Fields

name: String

Unique skill name (kebab-case: lowercase, hyphens, 1-64 chars). Must match the parent directory name per spec.

description: String

Human-readable description (max 1024 chars). Should describe what the skill does and when to use it.

location: PathBuf

Absolute path to the SKILL.md file.

license: Option<String>

SPDX license identifier or reference to a bundled license file.

compatibility: Option<String>

Environment requirements (intended product, system packages, etc.).

metadata: HashMap<String, String>

Arbitrary key-value metadata (author, version, tags, etc.).

allowed_tools: Vec<String>

Pre-approved tools the skill may use (space-delimited in SKILL.md).

shell: Option<String>

Preferred shell for inline commands: "bash" (default) or "powershell".

paths: Vec<String>

File path patterns for conditional activation. When set, the skill is only surfaced/activated when the user touches a file matching one of these glob patterns (e.g., ["*.py", "tests/**"]).

hooks: Option<HooksDefinition>

Hooks for intercepting tool calls.

Implementations

impl SkillDescriptor

pub fn catalog_line(&self) -> String

Generate a single catalog line for system-prompt injection.

Format: - <name>: <description> (with optional path constraints)

pub fn validate_name(&self) -> Vec<String>

Validate the name according to the agentskills.io spec. Returns a list of warnings (empty = valid).

pub fn validate_paths(&self) -> Vec<String>

Validate glob patterns in paths field. Returns a list of warnings for invalid or suspicious patterns.

pub fn matches_context_path(&self, context_path: &str) -> bool

Check whether a touched file path satisfies this skill’s conditional activation rules.

Skills without paths are always considered a match.

pub fn permits_tool(&self, tool_name: &str) -> bool

Check whether the descriptor permits use of a given tool name.

Empty allowed_tools means unrestricted. Match semantics mirror hook/tool matching so exact names, globs, and Bash -> Bash(git:*) prefix variants behave consistently.

Trait Implementations

impl Clone for SkillDescriptor

fn clone(&self) -> SkillDescriptor

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SkillDescriptor

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for SkillDescriptor

fn deserialize<__D>( __deserializer: __D, ) -> Result<SkillDescriptor, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for SkillDescriptor

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.