Tools & MCP
How agents reach beyond their own brain to act on the world.
What “tools” means
A tool is a function the agent can call. Examples:
get_order_status(order_id)— read from a systemsend_sms(phone, message)— act on the worldcreate_ticket(subject, body)— create a record somewhere
The LLM doesn’t actually execute the tool — it generates a structured call (function name + arguments), and the orchestrator runs it and feeds the result back.
What MCP is
Model Context Protocol — an open standard for how tools are exposed to LLMs. Anthropic introduced it; OpenAI and others have adopted it.
Before MCP, every framework (LangChain, LlamaIndex, custom code) had its own way of defining tools. After MCP, you write a tool once as an MCP server, and any MCP-compatible client can use it.
For Shipsy this matters because we have many customer systems to integrate. Each integration = one MCP server. Every agent in AgentFleet can then use any of those tools.
How tools get into Shipsy agents
- Engineering writes an MCP server for the customer system (e.g. SAP, customer CRM).
- The MCP server registers itself in Shipsy’s MCP registry.
- When an agent is configured, the CS person (in AgentFlow) picks which tools the agent has access to.
- At runtime, the agent decides when to call them.
Tool design rules
| Rule | Why |
|---|---|
| Each tool does one thing | LLMs pick better when tools are unambiguous |
| Inputs and outputs are typed and documented | LLM reads the docs in the prompt |
| Side effects are explicit in the name | update_order vs. cancel_order — not one manage_order |
| Errors are surfaced cleanly | LLM can retry or fall back if it understands the error |
| Tools are idempotent where possible | Retries don’t double-charge customers |
What CS folks need to remember
- Adding a new customer integration = writing one MCP server. Scope this with eng early.
- Existing tools are listed in the AgentFlow tool palette (and in the MCP server registry).
- If a customer asks “can the agent do X with their system”, the answer depends on whether the MCP server for X exists. Check first.
Sources
- Model Context Protocol spec
- See Tools & MCP integrations for Shipsy-specific tool inventory
Changelog
- 26 May 2026: Initial draft.