Customization File Constraints

These constraints apply to workspace prompt files such as INSTRUCTIONS.md and AGENTS.md:

Property	Value
Maximum size	1 MB; content beyond that is truncated with a warning on stderr.
Encoding	UTF-8; invalid bytes are replaced, not rejected.
Empty file	Treated as absent, so the default behavior applies.
Permissions	Unreadable file emits a warning on stderr and is skipped.

Project skills, commands, sub-agents, and MCP configs have their own required file layouts:

• Project skills
• Project commands
• Project sub-agents
• MCP servers