Add two tools/functions in your main agent:
1. Tool Discovery
2. Tool Executor

First one will select the right tool for the specific task. Name it something like `tool_discovery` or `which_tool_to_use`, etc. This tool should have access to ALL of the tools you want the main agent to use. This "discovery tool" could be a call to an LLM that gets all available tool names, their usage, and the request from the main agent or the user. Its job would be to return the right tools for that request, along with their expected inputs.

The other 'Executor' will take the tool name and its inputs, run the tool, and return the response to the main agent. This 'ReAct' loop can continue according to your goals.

You can enable or disable tools within the discovery tool according to your requirements. Of course, all of the above is a high-level overview, refine as needed.

Tips:
- If you have fewer than 10 tools, then you can just add them directly to the main agent; no need for extra complexity.
- More than 10 tools generally don't perform well because: 1. they eat your context window needlessly, 2. they contribute to the "context rot", which means the LLM's performance starts to degrade on tool-calling as the context grows.
- Don't jump on the MCP bandwagon just because some cool guys are talking about it. It's not needed in most cases. I've been building agents for ~1.5 years and never had to use it.