Capability Instructions

Instructions

Instructions are a host's always-loaded guidance text, supplied through PluginHost::instructions (the derive exposes it as instructions_fn). Like the status line and unlike the five tree surfaces, this one does not ride a file in the plugin tree — it is a string the host returns at runtime, delivered through each harness's native context channel.

2 backends deliver it today.

harness	how it arrives
claude	through the MCP initialize.instructions field — no separate file
opencode	a dedicated <plugin>-instructions.md, registered in opencode.json's instructions[] array

Every other backend has no always-loaded instruction channel agentgear targets, so the text is simply not delivered there. Because it sits outside the five-surface components IR (which has no field for it), a new backend cannot pick it up by rendering the IR — it needs explicit wiring like opencode's.

See also

• Capabilities — the index.
• Getting started — the instructions_fn derive attribute.
• Agent backends — the customization ceiling.