MCP
Tools and Schemas
MCPmcp / tools-and-schemas

Tools and Schemas

Understand how tool descriptors, machine-readable schemas, and example payloads should work together in the MCP section.

This page explains the contract layer, human explanation, machine-readable schemas, and stable examples should cooperate without collapsing into one noisy surface.

Before you continue

Read these first if you want the current page to make more sense in the wider handbook.

The three layers

The MCP section works best when it separates three different things:

1. Human explanation

This is the prose that tells a reader or agent what the surface is for.

2. Machine-readable schema

This is the strict contract used for validation and tooling.

3. Worked examples

This is the practical bridge between concept and contract.

Each layer has a different job.

Why collapse is bad

If explanation, schema, and examples all merge into one noisy payload:

  • machines parse less reliably
  • humans understand less clearly
  • maintenance becomes harder

The surface gets “richer”, but worse.

What good tool descriptors should emphasize

  • explicit naming
  • stable field contracts
  • narrow descriptions
  • predictable response shapes
  • obvious links to schema and examples

What good schemas should emphasize

  • strict field shape
  • predictable validation rules
  • minimal ambiguity
  • no decorative prose

What good examples should emphasize

  • real flow
  • correct sequencing
  • realistic payloads
  • easy comparison with schema