Struct Skill 

pub struct Skill {
    pub name: String,
    pub description: String,
    pub system_prompt: String,
    pub tools: Vec<String>,
    pub allowed_tools: Option<Vec<String>>,
    pub denied_tools: Option<Vec<String>>,
    pub metadata: HashMap<String, Value>,
}

Available on crate feature skills only.

A loaded skill definition.

Skills contain:

• A system prompt that defines agent behavior
• Tool configurations (which tools are available/denied)
• Optional metadata for custom extensions

Fields

name: String

Unique identifier for the skill.

description: String

Human-readable description of what the skill does.

system_prompt: String

The system prompt content (markdown body after frontmatter).

tools: Vec<String>

List of tool names that should be enabled for this skill.

If empty, all registered tools are available. If non-empty, it acts as a whitelist: only the listed tools (unioned with allowed_tools, and minus denied_tools) are available. See Skill::is_tool_allowed.

allowed_tools: Option<Vec<String>>

Optional list of tools explicitly allowed (whitelist). If set, only these tools are available.

denied_tools: Option<Vec<String>>

Optional list of tools explicitly denied (blacklist). These tools will be filtered out even if in tools list.

metadata: HashMap<String, Value>

Additional metadata from frontmatter.

Implementations

impl Skill

pub fn new(name: impl Into<String>, system_prompt: impl Into<String>) -> Self

Create a new skill with the given name and system prompt.

pub fn with_description(self, description: impl Into<String>) -> Self

Set the description.

pub fn with_tools(self, tools: Vec<String>) -> Self

Set the list of tools.

pub fn with_allowed_tools(self, tools: Vec<String>) -> Self

Set the allowed tools whitelist.

pub fn with_denied_tools(self, tools: Vec<String>) -> Self

Set the denied tools blacklist.

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

Check if a tool is allowed by this skill.

Resolution order:

• If the tool is in denied_tools, it is denied (highest precedence).
• Otherwise, if any whitelist is configured — either allowed_tools or a non-empty tools list — the tool must appear in the union of those lists. A non-empty tools list therefore restricts access, matching the documented skill-file format (tools: [read, grep]).
• If no whitelist is configured at all, the tool is allowed.

Trait Implementations

impl Clone for Skill

fn clone(&self) -> Skill

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Skill

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Skill

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Skill

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

where __S: Serializer,

Serialize this value into the given Serde serializer.