docs: reflect package-per-tool refactor

Amolith created

Update architecture section with expanded tools/ directory tree showing
specific package purposes. Remove placeholder context7 link template and
revise tool creation instructions.

Assisted-by: Claude Opus 4.5 via Crush <crush@charm.land>

Change summary

AGENTS.md | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)

Detailed changes

AGENTS.md 🔗

@@ -10,7 +10,6 @@ MCP server exposing Lunatask to LLMs. Primary use case is letting the user say "
 
 If you know what doc-agent is, use it to check go module APIs often. You can check context7 for details on various libraries directly if the MCP tools are available:
 
-- [link](target) (`/context7/id`) - description
 - [lunatask.app/api](https://lunatask.app/api) (`/websites/lunatask_app_api`) - Official Lunatask REST API documentation
 - [git.secluded.site/go-lunatask](https://git.secluded.site/go-lunatask) (`/websites/pkg_go_dev_git_secluded_site_go-lunatask`) - Go client for the Lunatask API
 - [github.com/charmbracelet/fang](https://github.com/charmbracelet/fang) (`/charmbracelet/fang`) - CLI starter kit with styled help, error handling, and version management for Cobra
@@ -32,7 +31,12 @@ task # before committing
 
 ```
 cmd/lunatask-mcp-server.go  → Config, tool registration, SSE server
-tools/                      → MCP tool handlers
+tools/
+  ├── areas/               → list_areas_and_goals tool
+  ├── habits/              → list_habits, track_habit tools
+  ├── tasks/               → create/update/delete_task tools
+  ├── timestamp/           → get_timestamp tool
+  └── shared/              → Provider interfaces, error helpers
 ```
 
 **Data flow**: SSE/STDIO request → MCP server → tool handler → lunatask client → Lunatask API
@@ -43,8 +47,10 @@ tools/                      → MCP tool handlers
 
 **New MCP tool**:
 
-1. Add handler method to `tools/` (on `Handlers` struct)
-2. Register tool with `mcpServer.AddTool()` in `cmd/lunatask-mcp-server.go`
+1. Create package in `tools/` with `Handler` type and `NewHandler()` constructor
+2. Add handler methods (`Handle`, `HandleCreate`, etc.) returning `(*mcp.CallToolResult, error)`
+3. Put description constants in `prose.go` within the package
+4. Register tool with `mcpServer.AddTool()` in `cmd/lunatask-mcp-server.go`
 
 ## Key Patterns