tools: discover prompts from ollie:prompt script headers

- Add Prompt field to tools.ToolInfo
- Add ExtractPrompt parser for ollie:prompt...ollie:end blocks
- Add DiscoverTools to scan tool scripts directory
- BuildRuntime appends discovered tool prompts to preamble

Tool scripts can now embed their usage documentation directly in
the script header. This replaces the separate tools-*.md prompt
files and ensures documentation stays co-located with implementation.

pkg/agent/core.go

@@ -24,6 +24,7 @@ import (
 	olog "ollie/pkg/log"
 	"ollie/pkg/paths"
 	"ollie/pkg/tools"
+	"ollie/pkg/tools/execute"
 )
 
 // toolClassifier reports whether a named tool is safe to run concurrently
@@ -51,6 +52,8 @@ func BuildRuntime(cfg *config.Config, d tools.Dispatcher, cwd string, env []stri
 		if listErr != nil {
 			messages = append(messages, fmt.Sprintf("list tools: %v", listErr))
 		}
+		// Append named tool scripts with their prompts.
+		allToolInfos = append(allToolInfos, execute.DiscoverTools()...)
 		for _, t := range allToolInfos {
 			serverOf[t.Name] = t.Server
 		}
@@ -160,6 +163,18 @@ func BuildRuntime(cfg *config.Config, d tools.Dispatcher, cwd string, env []stri
 		}
 	}
 
+	// Append tool prompts discovered from script headers.
+	var toolPrompts strings.Builder
+	for _, ti := range allToolInfos {
+		if ti.Prompt != "" {
+			toolPrompts.WriteString(ti.Prompt)
+			toolPrompts.WriteByte('\n')
+		}
+	}
+	if toolPrompts.Len() > 0 {
+		preamble += "\n" + toolPrompts.String()
+	}
+
 	return &Runtime{
 		Dispatcher:      d,
 		Tools:           allTools,

pkg/tools/execute/tool.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 
 	"ollie/pkg/paths"
+	"ollie/pkg/tools"
 )
 
 // ToolsPath returns the directory to search for named tool scripts.
@@ -162,6 +163,79 @@ func ansiCEscape(s string) string {
 	return b.String()
 }
 
+// ExtractPrompt parses the ollie:prompt ... ollie:end block from a tool
+// script's header comments. Returns the prompt text with comment prefixes
+// stripped, or "" if no prompt block is found.
+func ExtractPrompt(script string) string {
+	var lines []string
+	var inPrompt bool
+	for _, line := range strings.Split(script, "\n") {
+		trimmed := strings.TrimSpace(line)
+		// Strip comment prefix (# or //)
+		bare := trimmed
+		if strings.HasPrefix(bare, "# ") {
+			bare = bare[2:]
+		} else if strings.HasPrefix(bare, "#") {
+			bare = bare[1:]
+		} else if strings.HasPrefix(bare, "// ") {
+			bare = bare[3:]
+		} else if strings.HasPrefix(bare, "//") {
+			bare = bare[2:]
+		} else if inPrompt {
+			// Non-comment line while in prompt block — end of header
+			break
+		} else {
+			// Non-comment line before prompt block found
+			if trimmed != "" && !strings.HasPrefix(trimmed, "#!") {
+				break
+			}
+			continue
+		}
+
+		if strings.Contains(bare, "ollie:prompt") {
+			inPrompt = true
+			continue
+		}
+		if inPrompt && strings.Contains(bare, "ollie:end") {
+			break
+		}
+		if inPrompt {
+			lines = append(lines, bare)
+		}
+	}
+	if len(lines) == 0 {
+		return ""
+	}
+	return strings.Join(lines, "\n")
+}
+
+// DiscoverTools scans the tools directory and returns metadata for all scripts,
+// including their ollie:prompt blocks. Used to populate the /tools file and
+// inject tool prompts into the system prompt.
+func DiscoverTools() []tools.ToolInfo {
+	dir := ToolsPath()
+	entries, err := os.ReadDir(dir)
+	if err != nil {
+		return nil
+	}
+	var infos []tools.ToolInfo
+	for _, e := range entries {
+		if e.IsDir() || e.Name() == "idx" || strings.HasPrefix(e.Name(), ".") {
+			continue
+		}
+		data, err := os.ReadFile(filepath.Join(dir, e.Name()))
+		if err != nil {
+			continue
+		}
+		prompt := ExtractPrompt(string(data))
+		infos = append(infos, tools.ToolInfo{
+			Name:   e.Name(),
+			Prompt: prompt,
+		})
+	}
+	return infos
+}
+
 // ReadTool reads a named tool script from the tools directory.
 func ReadTool(name string) (string, error) {
 	if strings.Contains(name, "/") || strings.Contains(name, "..") {

pkg/tools/tools.go

@@ -14,6 +14,9 @@ type ToolInfo struct {
 	Name        string
 	Description string
 	InputSchema json.RawMessage
+	// Prompt is the usage documentation for this tool, extracted from
+	// the script's ollie:prompt block. Included in the system prompt.
+	Prompt      string
 }
 
 // Server is the interface satisfied by any tool server.