started prompt mechanics

docs/usage.md

@@ -22,6 +22,8 @@ In Copilot Chat, there are two distinct mechanisms:
 
 In this repository, skill guidance is exposed as MCP resources, not as server-owned prompt execution. Copilot remains the orchestrator.
 
+Prompt guidance is now exposed through both prompt resources and MCP prompt objects. Prompt objects are additive; authored markdown remains the canonical source.
+
 ## Background Mechanics
 
 ### What the server publishes
@@ -30,12 +32,18 @@ In this repository, skill guidance is exposed as MCP resources, not as server-ow
 
 1. `resource://catalog/skills_index`
 2. `resource://catalog/skills/{skill_id}`
+3. `resource://catalog/prompts_index`
+4. `resource://catalog/prompts/{prompt_id}`
 
 Each skill publishes a canonical Markdown document resource:
 
 1. `resource://skills/<skill-id>/document`
 2. `resource://skills/<skill-id>/references/<ref-id>`
 
+Prompts publish a canonical prompt document resource:
+
+1. `resource://prompts/<prompt-id>/document`
+
 The document payload is loaded from `docs/skills/<skill-id>/SKILL.md` and returned with metadata.
 
 ### What Copilot does as the client
@@ -74,6 +82,10 @@ In practice, there are two reliable ways to make skill content available in chat
 1. explicit resource attachment through `Add Context > MCP Resources` or `MCP: Browse Resources`
 2. MCP tool invocation using `list_resources`/`read_resource` (ResourcesAsTools), with thin catalog tools as parity fallback
 
+For prompt content, there is a third option when the client supports MCP prompt APIs:
+
+1. prompt-object discovery and invocation through MCP prompt lists and `get_prompt`
+
 Instruction quality and metadata quality still matter, because they influence whether Copilot recognizes that the MCP server is relevant and chooses the tool path well.
 
 ## Operating Pattern
@@ -209,6 +221,8 @@ Compatibility aliases for clients that use `catalog_*` naming are also available
 1. `catalog_search_patterns`
 2. `catalog_get_pattern_by_id`
 3. `catalog_get_skill_document_by_id`
+4. `catalog_search_prompts`
+5. `catalog_get_prompt_by_id`
 
 Use canonical names first; aliases exist only to preserve interoperability when a client emits non-canonical names.