modify-agent

Modify LangGraph/LangChain agents by updating models, instructions, and MCP tools.

Updated May 10, 2026
One-click install
npx skills add https://github.com/keqingli1129/agent-langgraph-one --skill modify-agent-keqingli1129
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: modify-agent
Source: https://github.com/keqingli1129/agent-langgraph-one/tree/main/.claude/skills/modify-agent
Command: npx skills add https://github.com/keqingli1129/agent-langgraph-one --skill modify-agent-keqingli1129

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

This Skill helps you quickly modify agent code, add new tools, and adjust configuration without breaking SDK patterns or tracing/integration expectations.

Core Features & Use Cases

  • Agent code edits: Update core logic, model selection, and system instructions in the right files (e.g., agent_server/agent.py).
  • Tool expansion (MCP + SDK): Add MCP servers (Databricks-hosted and external) and integrate them via the LangChain Databricks MCP client.
  • Safe instruction customization: Apply system instructions correctly (via prepending messages in LangGraph) rather than unsupported create_agent parameters.

Quick Start

Tell the agent: "Modify agent_server/agent.py to add an MCP tool, switch to an appropriate model endpoint, and update the system instructions using the correct message-prepending pattern."

Frequently Asked Questions about modify-agent

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I add MCP tools to an existing LangGraph agent?

To add MCP tools to a LangGraph agent, you integrate Databricks-hosted or external MCP servers via the LangChain Databricks MCP client, wiring them using DatabricksMCPServer or DatabricksMultiServerMCPClient and steering edits to agent_server/agent.py.

What is the correct way to update system instructions in LangGraph?

The correct way to update system instructions in LangGraph is by prepending messages to the conversation history, rather than passing unsupported parameters to the create_agent function, ensuring safe instruction customization without breaking SDK patterns.

Can I change the model selection for a LangChain agent without breaking configuration?

Yes, you can change model selection by steering edits to agent_server/agent.py to switch to an appropriate model endpoint, ensuring the modification satisfies functional requirements for serving and evaluation without breaking tracing or integration expectations.

Does this approach support integrating Databricks SDK usage with MCP servers?

Yes, this approach supports integrating Databricks SDK usage by applying edits to agent_server/agent.py and wiring tools through DatabricksMCPServer and DatabricksMultiServerMCPClient, maintaining correct SDK patterns during agent modification.

Why should I prepend messages instead of using create_agent parameters for system instructions?

You should prepend messages because using unsupported create_agent parameters for system instructions breaks SDK patterns, whereas the message-prepending pattern applies system instructions correctly in LangGraph workflows without disrupting tracing or integration expectations.

What's the best way to modify agent code to expand tools and adjust configuration safely?

The best way to modify agent code safely is to steer edits to agent_server/agent.py, updating core logic, model selection, and tool integrations while using the correct message-based system instruction pattern to avoid breaking SDK patterns.