An agent file defines a custom agent, and its frontmatter is the block of settings at the top of the file. When Claude Code loads an agent file that comes from a plugin (an add-on that extends Claude Code), it now logs a warning for any frontmatter setting it does not recognize, and suggests the closest valid name. For example:
allowedtoolspoints totoolswhentousepoints todescription
Plugin agents already warned that permissionMode, hooks and mcpServers are ignored for them. They now also warn that these are ignored:
initialPromptobserverobserverMessageobserveSubagents
The warning suggests defining the agent in .claude/agents/ to use such a setting.
Before, a misspelled setting in agent frontmatter was dropped without any message, so an agent could quietly run without the setting its author meant to give it. The warning now shows where the mistake is.