bianhaifeng789-hue/deferred-tool-filter

Deferred Tool Filter Skill

Overview

Problem: Large MCP server catalogs (100+ tools) consume context window.

Solution:

• List tools by name in system prompt
• tool_search tool for runtime discovery
• Reduced context + improved accuracy

Configuration

tool_search:
  enabled: true
  # Tools discoverable via tool_search, not pre-loaded

Benefits

| Metric | Before | After | |--------|--------|-------| | Context usage | 50K+ tokens | ~2K tokens | | Tool selection | Often confused | More accurate | | Discovery | All tools loaded | On-demand search |

Tool Search Usage

// Agent wants to use a tool but doesn't know details
const result = await tool_search({
  query: "database query",
  max_results: 5
});

// Returns matching tools with descriptions
result.tools.forEach(t => {
  console.log(`${t.name}: ${t.description}`);
});

Filter Logic

function filterTools(allTools, deferredEnabled) {
  if (!deferredEnabled) return allTools;

  // 1. Core tools always loaded (file, bash, web)
  const core = allTools.filter(t => !t.mcp_server);

  // 2. MCP tools listed in prompt, not loaded
  const mcp = allTools.filter(t => t.mcp_server);
  const mcpNames = mcp.map(t => t.name);

  // 3. Add tool_search to core
  core.push(tool_search_tool);

  return {
    loaded: core,
    discoverable: mcpNames
  };
}

Integration Points

1. Tool loading - Filter before agent init
2. System prompt - Add discoverable tool names
3. tool_search tool - Runtime discovery

OpenClaw Integration

Integrates with:

• MCP server management
• Context optimization
• Tool registry

Status

• ✅ Skill documentation created
• 🔜 Implementation pending (config-based)