# Hermes Agent MCP tool missing or failing

> Separate discovery, connection, authentication and operation failures using one known read-only request.

Canonical: https://hermeswatcher.com/troubleshoot/mcp-tool-missing-or-failing  
Section: Troubleshooting · Skills, plugins & MCP  
Last reviewed: Oct 19, 2026  
Basis: Explained from the official Hermes Agent docs and repository (Nous Research). Steps follow the linked official sources.

## Classify the first failure

Record the server name, active profile, expected tool and first meaningful error. If no tool appears, inspect whether the server is configured and whether tool filters or enabled toolsets exclude it. If discovery succeeds but connection fails, focus on the server process or URL, executable availability and initialization errors before changing the prompt.

For an authorization failure, verify which account and scopes the integration actually uses. The official MCP guide documents an explicit hermes mcp login flow for applicable OAuth servers. Complete authentication through the documented flow rather than pasting tokens into chat or copying credentials between unrelated profiles.

## Use a small discriminating check

Choose a known object the account is allowed to read. If listing works but opening the object fails, investigate item-level access or an identifier mismatch. If one tool works and another fails, retain both requests and results; that difference is more useful than repeatedly reconnecting the whole server.

Distinguish a connection timeout from a tool-call timeout. The current guide documents separate timeout settings for those stages. Increase a limit only when evidence shows legitimate work needs longer, rather than using a large timeout to conceal a dead process. After repair, repeat the same small request and inspect the returned data before resuming a large workflow.

## Expected result and limits

A passing check returns the expected object from the intended account through the intended tool. It does not establish write authorization or every server capability. This guide covers Hermes-side diagnosis; server-specific setup and provider permissions require that server's own primary documentation. No third-party server has been tested for this entry.

## Related tools

- [Turn a crowded inbox into a review queue](https://hermeswatcher.com/workflows/inbox-triage.md)
- [Build a useful GitHub issue review](https://hermeswatcher.com/workflows/github-issue-review.md)
- [MCP: connect external tool servers](https://hermeswatcher.com/tools/mcp.md)

## Sources

- [MCP Integration](https://hermes-agent.nousresearch.com/docs/user-guide/features/mcp)
- [Tools & Toolsets](https://hermes-agent.nousresearch.com/docs/user-guide/features/tools)

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HermesWatcher is an independent guide. It is not affiliated with or endorsed by Nous Research. The [official Hermes Agent documentation](https://hermes-agent.nousresearch.com/docs) and [repository](https://github.com/NousResearch/hermes-agent) from Nous Research are the authority; each page here lists the official sources it was written from. If this site and the official docs disagree, trust the official docs. Index for agents: https://hermeswatcher.com/llms.txt