New Cohort Starts:

Donate
← Back to the skill map
AI Systems/AI & reliability

Tool Use & MCP

6 micro-topics in AI Systems, each with the evidence that proves you have it and the written reason behind every link. Before you start, it rests on 4 other domains. Downstream, it holds up 1 domain.

6 topics  ·  depth 8–10 of 16  ·  5 internal links  ·  4 in  ·  3 out

Before you start

Load-bearing links first. Each one says what in this domain rests on what outside it, and why.

API Contracts

1 link

load-bearing

Declare tools for a model rests on Design an API contract

A tool declaration is a contract for the model.

FastAPI

1 link

load-bearing

Expose capability over MCP rests on Route requests in FastAPI

A server exposes the tools.

Model Foundations

1 link

load-bearing

Draw the model boundary rests on Reason about nondeterministic output

The boundary exists because model output varies.

Model Integration

1 link

load-bearing

Declare tools for a model rests on Get structured output

Tool arguments arrive as structured output.

What you will be able to do

In prerequisite order. Each idea names the artifact that closes it, the market demand that put it on the map, and what it stands on.

Depth 8  ·  representational  ·  scaffolded  ·  M17 §17.5

Declare tools for a model

Describes callable functions and their schemas

Evidence
A model calls the right tool with valid arguments
Market anchor
Function calling
Rests on
load-bearing

Design an API contract · API Contracts

A tool declaration is a contract for the model.

load-bearing

Get structured output · Model Integration

Tool arguments arrive as structured output.

Depth 9  ·  procedural  ·  scaffolded  ·  M17 §17.5

Execute and return tool results

Runs the call and feeds the result back

Evidence
Completes a round trip through a real tool
Market anchor
Function calling
Rests on
load-bearing

Declare tools for a model

You execute a call you declared.

Depth 9  ·  representational  ·  guided  ·  M20 §20.2

Expose capability over MCP

Serves tools through a standard protocol

Evidence
A separate client uses the same tools unmodified
Market anchor
Model Context Protocol
Rests on
load-bearing

Declare tools for a model

MCP standardizes declarations you can already write.

load-bearing

Route requests in FastAPI · FastAPI

A server exposes the tools.

Depth 10  ·  conceptual  ·  guided  ·  M17 §17.5

Orchestrate multiple tools

Handles several calls, including in parallel

Evidence
Resolves a task requiring two different tools
Market anchor
AI agents
Rests on
load-bearing

Execute and return tool results

Multiple calls extend one call.

Depth 10  ·  conceptual  ·  scaffolded  ·  M17 §17.5

Recover from tool failure

Handles a tool that errors or returns nothing

Evidence
A failed tool call does not end the interaction
Market anchor
Reliability engineering
Rests on
load-bearing

Execute and return tool results

Recovery handles a call that ran and failed.

Depth 10  ·  meta  ·  scaffolded  ·  M20 §20.4

Draw the model boundary

Decides what the model does and what code does

Evidence
Justifies why a step is deterministic code, not a prompt
Market anchor
AI architecture
Rests on
load-bearing

Execute and return tool results

You can only draw the line once you have seen both sides run.

load-bearing

Reason about nondeterministic output · Model Foundations

The boundary exists because model output varies.

What rests on this domain

Everything downstream that names an idea here as a prerequisite, grouped by where it lives.

Agents

3 links

load-bearing
load-bearing

Decide when a step needs an agent rests on Draw the model boundary

The agent question is the model boundary drawn one level up.

supporting

Run an agent loop rests on Recover from tool failure

Loops depend on surviving individual tool failures.

Retool. Retrain. Relaunch.

375 ideas. 17 weeks. No tuition, ever.

Vets Who Code is a veteran-run 501(c)(3). The accelerator is free, remote, and we don’t take a share of your first paycheck.

Free · Remote · 17 weeks · EIN 86-2122804