The `.agent.md` file extension is not defined in the frontmatter schema mapping configuration.

[WilliamBerryiii]

The .agent.md file extension is not defined in the frontmatter schema mapping configuration. According to scripts/linting/schemas/schema-mapping.json, only .chatmode.md, .prompt.md, and .instructions.md file extensions have defined schemas. This file will either fail frontmatter validation or fall back to the base schema which doesn't validate the tools field.

Consider either:

1. Using .chatmode.md extension instead (as chatmodes support agent mode and tools)
2. Adding a new schema mapping for .agent.md files to scripts/linting/schemas/schema-mapping.json

The existing chatmode schema supports both the description and tools fields used in this frontmatter.

Originally posted by @Copilot in #82 (comment)