Access supplementary documentation, templates, or data from a skill.

Resources are additional files that support skill execution. They can be static
content (markdown docs, templates, schemas) or dynamic callables (functions that
generate content based on parameters).

When to use this:
- When a skill's instructions reference a specific resource
- To access form templates, reference documentation, or data schemas
- When you need supplementary information beyond the skill instructions

Returns:
The resource content as a string.

Important:
- Always call `load_skill(skill_name)` first in this run
- Get resource names from the skill's documentation first
- Use exact resource names - do not modify or guess
- Check if the resource requires arguments (check its schema)
- Static files don't need args; callables may require them
