Proposal: Tool categories and filtering

[hemanth]

Context

When a page registers many tools, agents need a way to discover relevant ones efficiently.

Problem

Our MCP bridge can expose 50+ tools from a server. Without categorization:

• Agents must parse all tool descriptions
• Token limits are consumed by irrelevant tools
• Users see overwhelming tool lists

Proposal

Support tool categorization and filtering:

navigator.modelContext.provideContext({
  tools: [
    {
      name: "search_proposals",
      description: "Search TC39 proposals",
      category: "search",
      tags: ["tc39", "javascript", "ecmascript"],
      inputSchema: { ... },
      execute: async (args) => { ... }
    },
    {
      name: "get_proposal",
      description: "Get proposal details",
      category: "read",
      tags: ["tc39", "javascript"],
      inputSchema: { ... },
      execute: async (args) => { ... }
    },
    {
      name: "compare_proposals",
      description: "Compare two proposals",
      category: "analysis",
      tags: ["tc39", "comparison"],
      inputSchema: { ... },
      execute: async (args) => { ... }
    }
  ]
});

Agent-Side Filtering

// Agent can query for relevant tools
const searchTools = await navigator.modelContext.getTools({ 
  category: "search" 
});

const tc39Tools = await navigator.modelContext.getTools({ 
  tags: ["tc39"] 
});

// Or filter by capability
const readOnlyTools = await navigator.modelContext.getTools({
  capabilities: ["read"] // vs "write", "delete"
});

Standard Categories

Category	Description
search	Find/query information
read	Retrieve specific data
create	Create new resources
update	Modify existing resources
delete	Remove resources
analysis	Process/analyze data
navigation	Page/UI navigation
media	Images, audio, video

Benefits

1. Efficient tool discovery for agents
2. Better UX when displaying available tools
3. Permission scoping by category
4. Reduced token usage in prompts

This aligns with the proposal's goal of making complex interfaces more navigable for agents.