What it does
Paste an F5 BIG-IP AS3 declaration, the JSON you POST to /mgmt/shared/appsvcs/declare, and this reads it back to you: whether it is a full AS3 request or an ADC-only declaration, the top-level options, the ADC metadata, and the Tenant to Application to resource tree with every class named and explained. It also checks the structural rules F5 documents. It is a decode-only tool that runs entirely in your browser, grounded in F5's AS3 user guide and schema reference.
Request or declaration
The first thing it tells you is which of two shapes you pasted. A full AS3 request has class: "AS3" and carries action (deploy, dry-run, retrieve, remove, patch) and persist, wrapping the declaration. An ADC-only declaration has class: "ADC" at the top and omits the wrapper, which means the action and persist options are not available. The tool surfaces the action and persist for a request, and the schemaVersion, id, label, and remark for the ADC declaration either way.
The tree it walks
Below the metadata, the tool walks the fixed AS3 hierarchy: each Tenant (which becomes a BIG-IP partition), each Application (with its template, noting when generic is defaulted in AS3 3.20 and later), and each resource object inside. For every object it shows the class and a plain-language explanation, from Service_HTTP and Service_HTTPS through Pool, Monitor, TLS_Server, TLS_Client, Certificate, Persist, WAF_Policy, Endpoint_Policy, and iRule. A class it does not recognize is still listed and marked, never hidden.
The structural checks
Alongside the explanation, the tool applies the documented rules that make a declaration valid: a top-level AS3 or ADC class, a required schemaVersion, at least one Tenant containing at least one Application containing at least one resource, and the template and service-class matching rule (a template of http, https, tcp, udp, or l4 requires a matching Service object named service, formerly serviceMain). It also flags reserved names (Common, Shared, service) as informational and checks that object names follow the 1 to 64 character, letter-first, alphanumeric rule.
Scope and grounding
This is a structure explainer and sanity checker, not a full JSON-Schema validator. It does not reproduce the entire AS3 schema or check every property, so a declaration that passes here can still be rejected by AS3 itself; treat a clean result as a good sign rather than a guarantee. Nothing you paste is uploaded or leaves the page. Grounded in F5's AS3 documentation; for a deployment, validate against your AS3 version and the schema reference.