The A2A Agent Card: what it must contain

An A2A server has to publish an Agent Card. This guide lists the fields the specification requires, the optional ones, and the slips that confuse clients.

An Agent Card is a JSON document in which an A2A server describes itself: who it is, where it can be reached, which features it supports, what it can do and how a caller must authenticate. The specification says that every A2A server must make one available (A2A specification). Clients read it before they send a single task, so a card with a missing field, a wrong name or an optimistic feature flag causes failures that look like network or protocol bugs. This guide lists what the card must contain, where it lives, and the slips that most often make a client misread it.

Read the full report on AISkills402: https://aiskills402.com/blog/a2a-agent-card-required-fields?utm_source=devto&utm_medium=social