Operating rules

Use scripts/rest_request.py for all ProteomeXchange PROXI calls.
Use base_url=https://proteomecentral.proteomexchange.org/api/proxi/v0.1.
Collection endpoints are better with max_items=10; targeted identifier lookups usually do not need max_items.
Keep requests narrow by identifier, spectrum, or dataset whenever possible.
Re-run requests in long conversations instead of relying on older tool output.
Treat displayed ... in tool previews as UI truncation, not literal request content.

Execution behavior

Return concise markdown summaries from the script JSON by default.
Prefer these paths: datasets, datasets/<identifier>, libraries, peptidoforms, proteins, psms, spectra, and usi_examples.
If the user needs the full payload, set save_raw=true and report the saved file path.