# NousResearch/hermes-agent · Cap MCP tool result size to prevent unbounded allocation

## Open now

- Nothing open on GitHub.

These issues and pull requests address a risk where MCP tool results have no size limit, potentially causing unbounded memory allocation. The proposed fix involves truncating or capping oversized tool results.

## TL;DR

- 5 member(s): 0 open issue(s), 1 closed issue(s), 0 open PR(s), 1 merged PR(s), 3 PR(s) closed without merging.
- A fix was merged to main in PR #90336. Verify it addresses your case.
- **Recommended:** read PR #90336 (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evidence (`STRUCTURAL_SPANNING`): every member is connected by structural evidence: shared changed files, or a closing/superseded reference.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 `0.40`: 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

- #56059: MCP tool results have no size limit — unbounded allocation risk

## Prior & competing PRs

- **#90336: feat: MCP results spill at 50K and flag provider-side elision (Composio eval findings)**. merged to main · fix tier `verified`
  - maintainer direction: category `merged`; implication `superseded`
  - files: `agent/tool_dispatch_helpers.py`, `agent/tool_executor.py`, `cli-config.yaml.example`, `tests/agent/test_tool_dispatch_helpers.py`, `tests/tools/test_budget_config.py`, `tests/tools/test_mcp_result_size_limit.py`, `tests/tools/test_tool_result_storage.py`, `tools/budget_config.py`, `tools/mcp_tool.py`, `tools/tool_result_storage.py`, `website/docs/user-guide/configuration.md`
- **#56060: fix: cap MCP tool result size to prevent unbounded allocation**. closed without merge
  - maintainer direction: category `implemented_elsewhere`; implication `superseded`; refs `4a83b03c3`, `#90336`, `#56059`, `#90336`
- **#56068: fix(mcp): cap tool result size**. closed without merge
  - maintainer direction: category `duplicate_of`; implication `duplicate`; refs `#56060`, `#56059`, `#56060`, `#44172`, `#24444`
- **#56072: fix(tools): truncate oversized MCP tool results to prevent unbounded allocation (#56059)**. closed without merge
  - maintainer direction: category `implemented_elsewhere`; implication `superseded`; refs `4a83b03c3`, `#90336`, `#56059`, `#90336`

## Fix status

- Merged to main in PR #90336 (cited above). No release data is tracked. Verify downstream.
- Fix last verified (merged) `2026-08-19`.
- Subsystem: `mcp`