# NousResearch/hermes-agent · MCP SDK 2.x read-only hint attribute casing bug

## Open now

- Nothing open on GitHub.

These items concern a bug where the MCP trust gate fails to detect read-only tool hints in SDK 2.x due to a camelCase vs. snake_case attribute naming mismatch. A fix to support the snake_case \`read_only_hint\` attribute is included.

## TL;DR

- 3 member(s): 0 open issue(s), 1 closed issue(s), 0 open PR(s), 1 merged PR(s), 1 PR(s) closed without merging.
- A fix was merged to main in PR #133532. Verify it addresses your case.
- **Recommended:** read PR #133532 (and any competing PRs below) before filing. Confirm the merged change covers your symptom.

## Maintainer resolution verdict

- Internal-tracker verdict over this cluster's issue members: `unresolved`. This is distinct from the fix status above. Weigh it yourself.

## How this cluster was grouped

- Link evidence (`STRUCTURAL_SPANNING`): every member is connected by structural evidence: shared changed files, or a closing/superseded reference.
- Pairwise link density `0.67`: the share of member pairs that carry a link, counting a structural link in full and a relevance-only link at 0.36. `1.00` means every pair is linked.

## Closed / duplicate issues

- #109817: MCP trust gate never sees readOnlyHint on mcp SDK 2.x: \`_annotation_read_only_hint\` reads the camelCase attribute

## Prior & competing PRs

- **#133532: MCP read-only tools on untrusted servers stop asking for approval under mcp 2.x (salvage #111270)**. merged to main · fix tier `verified`
  - maintainer direction: category `merged`
  - files: `contributors/emails/[redacted:email]`, `tests/e2e/core/mcp_plugins/test_mcp_stdio_conformance.py`, `tests/tools/test_mcp_trust_gating.py`, `tools/mcp_tool_registration.py`
- **#111618: fix(tools): support snake_case read_only_hint in MCP SDK 2.x**. closed without merge
  - maintainer direction: category `implemented_elsewhere`; implication `superseded`; refs `4b6884aaa7`, `#133532`, `#111270`, `#88372`

## Fix status

- Merged to main in PR #133532 (cited above). No release data is tracked. Verify downstream.
- Fix last verified (merged) `2026-10-05`.