# NousResearch/hermes-agent · MCP string tool argument validation and crash fix

## Open now

- 1 issue, 1 PR open on GitHub.
- #21960: \[Bug\]: mcp_serve string tool args can crash on malformed external client inputs
- PR #21723: fix(mcp): validate string tool args defensively

These members address a bug where malformed external client inputs to MCP string tool arguments can cause a crash, along with defensive validation fixes to handle such inputs safely.

## TL;DR

- 3 member(s): 1 open issue(s), 0 closed issue(s), 1 open PR(s), 0 merged PR(s), 1 PR(s) closed without merging.
- No fix has been merged to main; one or more PRs were attempted (see below).
- **Recommended:** review the prior/competing PR(s) below. A fix was attempted but not merged; your case may extend or revive that work.

## 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evidence (`STRUCTURAL_SPANNING`): every member is connected by structural evidence: shared changed files, or a closing/superseded reference.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.

## Open related issues

- #21960: \[Bug\]: mcp_serve string tool args can crash on malformed external client inputs

## Prior & competing PRs

- **#21723: fix(mcp): validate string tool args defensively**. open
  - maintainer direction: category `uncategorized`; implication `needs_llm`; refs `1c793f19572a`
  - files: `mcp_serve.py`, `tests/test_mcp_serve.py`
- **#21968: fix(mcp): validate string tool arguments**. closed without merge
  - maintainer direction: category `stale_abandoned`; implication `active`

## Fix status

- No merged fix on record.
- Subsystem: `mcp`