[DOCS] Clarify behavior of `agent` field when `context` is not set to `fork`

Documentation Type

Unclear/confusing documentation

Documentation Location

https://code.claude.com/docs/en/skills#available-metadata-fields

Section/Topic

The agent field entry within the "Available metadata fields" table in the Agent Skills documentation.

Current Documentation

The agent field description states:

"Specify which agent type to use when context: fork is set (e.g., Explore, Plan, general-purpose, or a custom agent name from .claude/agents/). Defaults to general-purpose if not specified. Only applicable when combined with context: fork."

What's Wrong or Missing?

While the documentation mentions the field is "only applicable" when combined with context: fork, it does not explicitly state the behavior when a user defines an agent but leaves the context as inline (the default). It is unclear whether this configuration triggers a validation error, a warning, or is silently ignored.

Suggested Improvement

The documentation should explicitly state that the agent field is ignored if the context is not set to fork.

Suggested Text:

"Specify which agent type to use when context: fork is set (e.g., Explore, Plan, general-purpose, or a custom agent name from .claude/agents/). Defaults to general-purpose if not specified. This field is ignored unless context is set to fork."

Impact

High - Prevents users from using a feature

Additional Context

• This relates directly to the context field documented immediately above it: https://code.claude.com/docs/en/skills#available-metadata-fields
• Explicitly defining "ignored" behavior helps developers avoid confusion when a Skill executes in the main thread despite an agent being specified in the metadata.