Load complete instructions and capabilities for a specific skill.

A skill contains detailed instructions and supplementary resources (like templates
or reference docs). Load a skill when you need to perform a task within its domain.

Returns:
Structured documentation containing:
- Skill name, description, and source location
- Available resources: supplementary files with their parameters
- Detailed instructions: step-by-step guidance for using the skill

Important:
- Read the entire instructions section before taking action
- Call this before using `read_skill_resource` for this skill
- Resource names are authoritative - use exact names from the output
- Do NOT infer or guess resource names
- Check parameter schemas if resources require arguments
