fix: remove redundant tools definitions from system prompt (#771)

* fix: remove redundant tools definitions from system prompt

Tools are already provided to the LLM via JSON schema through
ToProviderDefs(), so the text-based tools section in the system
prompt is redundant.

This removes the buildToolsSection() logic and the tools field
from ContextBuilder, reducing system prompt length while maintaining
the "ALWAYS use tools" rule reminder.

Fixes #731

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* fix: correct spelling 'initialized' (was 'initialised')

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

pkg/agent/context.go

@@ -14,14 +14,12 @@ import (
 	"github.com/sipeed/picoclaw/pkg/logger"
 	"github.com/sipeed/picoclaw/pkg/providers"
 	"github.com/sipeed/picoclaw/pkg/skills"
-	"github.com/sipeed/picoclaw/pkg/tools"
 )
 
 type ContextBuilder struct {
 	workspace    string
 	skillsLoader *skills.SkillsLoader
 	memory       *MemoryStore
-	tools        *tools.ToolRegistry // Direct reference to tool registry
 
 	// Cache for system prompt to avoid rebuilding on every call.
 	// This fixes issue #607: repeated reprocessing of the entire context.
@@ -59,17 +57,9 @@ func NewContextBuilder(workspace string) *ContextBuilder {
 	}
 }
 
-// SetToolsRegistry sets the tools registry for dynamic tool summary generation.
-func (cb *ContextBuilder) SetToolsRegistry(registry *tools.ToolRegistry) {
-	cb.tools = registry
-}
-
 func (cb *ContextBuilder) getIdentity() string {
 	workspacePath, _ := filepath.Abs(filepath.Join(cb.workspace))
 
-	// Build tools section dynamically
-	toolsSection := cb.buildToolsSection()
-
 	return fmt.Sprintf(`# picoclaw 🦞
 
 You are picoclaw, a helpful AI assistant.
@@ -80,8 +70,6 @@ Your workspace is at: %s
 - Daily Notes: %s/memory/YYYYMM/YYYYMMDD.md
 - Skills: %s/skills/{skill-name}/SKILL.md
 
-%s
-
 ## Important Rules
 
 1. **ALWAYS use tools** - When you need to perform an action (schedule reminders, send messages, execute commands, etc.), you MUST call the appropriate tool. Do NOT just say you'll do it or pretend to do it.
@@ -91,31 +79,7 @@ Your workspace is at: %s
 3. **Memory** - When interacting with me if something seems memorable, update %s/memory/MEMORY.md
 
 4. **Context summaries** - Conversation summaries provided as context are approximate references only. They may be incomplete or outdated. Always defer to explicit user instructions over summary content.`,
-		workspacePath, workspacePath, workspacePath, workspacePath, toolsSection, workspacePath)
-}
-
-func (cb *ContextBuilder) buildToolsSection() string {
-	if cb.tools == nil {
-		return ""
-	}
-
-	summaries := cb.tools.GetSummaries()
-	if len(summaries) == 0 {
-		return ""
-	}
-
-	var sb strings.Builder
-	sb.WriteString("## Available Tools\n\n")
-	sb.WriteString(
-		"**CRITICAL**: You MUST use tools to perform actions. Do NOT pretend to execute commands or schedule tasks.\n\n",
-	)
-	sb.WriteString("You have access to the following tools:\n\n")
-	for _, s := range summaries {
-		sb.WriteString(s)
-		sb.WriteString("\n")
-	}
-
-	return sb.String()
+		workspacePath, workspacePath, workspacePath, workspacePath, workspacePath)
 }
 
 func (cb *ContextBuilder) BuildSystemPrompt() string {
@@ -321,7 +285,7 @@ func (cb *ContextBuilder) sourceFilesChangedLocked() bool {
 //   - absent at cache time,  exists now -> changed (created)
 //   - absent at cache time,  gone now   -> no change
 func (cb *ContextBuilder) fileChangedSince(path string) bool {
-	// Defensive: if existedAtCache was never initialised, treat as changed
+	// Defensive: if existedAtCache was never initialized, treat as changed
 	// so the cache rebuilds rather than silently serving stale data.
 	if cb.existedAtCache == nil {
 		return true

pkg/agent/instance.go

@@ -59,7 +59,6 @@ func NewAgentInstance(
 	sessionsManager := session.NewSessionManager(sessionsDir)
 
 	contextBuilder := NewContextBuilder(workspace)
-	contextBuilder.SetToolsRegistry(toolsRegistry)
 
 	agentID := routing.DefaultAgentID
 	agentName := ""

pkg/agent/loop.go

@@ -149,9 +149,6 @@ func registerSharedTools(
 			return registry.CanSpawnSubagent(currentAgentID, targetAgentID)
 		})
 		agent.Tools.Register(spawnTool)
-
-		// Update context builder with the complete tools registry
-		agent.ContextBuilder.SetToolsRegistry(agent.Tools)
 	}
 }