Published free diagnostic
A2A Agent Card validator
Check the static discovery contract, preserve the version boundary, and leave remote behavior unclaimed.
Strict-current evidence
Identity, implementation version, supported A2A 1.0 interfaces, media modes, capabilities, and complete skill descriptions are evaluated as the current contract.
Legacy interoperability
Older root endpoint and transport fields receive a separate verdict. They may explain compatibility, but cannot make the current document pass.
Questions
Does a valid Agent Card prove the agent works?
No. This is a static document check. It does not contact an interface, authenticate, send a message, exercise a skill, or certify safety.
Why are current and legacy results separate?
A legacy 0.3 field can help an older client interoperate, but it must not upgrade the strict A2A 1.0 verdict. Separate results preserve that evidence boundary.