github_get_pr / github_get_issue cut the body at 2000 chars, so an append via github_edit_pr can drop content #41

Seen (designSystem-9062, 2026-10-19): the agent couldn't safely append to an existing PR body because the read returned a truncated body.

Verified: read_tools.py:316 and :343 slice body[:2000] with no truncation marker. An agent that reads, appends and writes back silently deletes everything after 2000 chars.

Fix: return the full body (it's bounded by _MAX_PR_CHARS already, or add a body_max_chars/paging arg), and say [truncated: N of M chars] whenever it does cut. Consider an append mode on github_edit_pr so appends never round-trip the body.

Filed from protoagent fleet friction triage 2026-10-21. Root-cause claims are the agent's unless noted as verified.