Hermes Tool Slimmer: plugin for Hermes Agent

Hermes Agent plugin that sends only the relevant tool schemas with each model request

What Hermes Tool Slimmer does

Every Hermes model call carries the JSON schema of every enabled tool, which the README puts at roughly 15 to 20k tokens per request on installs with dozens of native and MCP tools. Tool Slimmer ranks tools against the current prompt with BM25, using boosts for name, toolset, parameters and aliases, then sends the always-on tools plus the top matches. The default keyword mode is fully local, with no embeddings, extra model calls or network access.

On a 38-tool Hermes install, averaged over 40 prompts, the README reports about 15.1k tool tokens per request without slimming, about 7.9k in keyword mode and about 4.3k in the experimental jev mode. The selector fails open by sending the original tool list on any error, and a built-in tool_slimmer_request_full_tools fallback lets the model ask for the full catalog on the next request. On Hermes v0.19 and later it hooks in through the built-in llm_request middleware, so no core patch is needed.

Key features

BM25 keyword ranking with name, toolset, parameter and alias boosts
Fails open to the original tool list, plus a full-catalog fallback tool
Separate profiles and include or exclude lists for Telegram, Slack, CLI, cron and webhooks
Dashboard with savings, recent decisions, guided setup and a tool index browser
A dry_run setting to watch decisions before changing any request
Leaves approval prompts, disabled tools, auth and safety policy untouched

When to use it

Cutting per-request token cost on a Hermes install with dozens of native and MCP tools
Giving messaging, cron and CLI entry points different tool budgets
Checking in dry-run mode how much a trimmed tool list would save before enabling it

Who it is for: Hermes Agent users running many native or MCP tools who want to cut the tool-schema tokens sent on every model call.

How it fits with Hermes Agent

It is a Hermes Agent plugin that hooks into the llm_request middleware on Hermes v0.19 and later, and it adds a hermes tool-slimmer command and a dashboard plugin.

How to install Hermes Tool Slimmer

These commands are copied from the project's README. Check the repository for the latest steps before you run them.

git clone https://github.com/aliasocracy/hermes-tool-slimmer.git "$HOME/hermes-tool-slimmer"
bash "$HOME/hermes-tool-slimmer/scripts/install-hermes-tool-slimmer.sh"
hermes tool-slimmer doctor

Requirements: A Hermes Agent install on the same machine; Hermes v0.19 or later needs no core patch

Note: The jev selector mode is labelled experimental in the README.

FAQ

What is Hermes Tool Slimmer?

Hermes Tool Slimmer is a Hermes Agent plugin that reduces tool-schema overhead by sending only the tools relevant to the current turn. It ranks tools against your prompt and sends the always-on tools plus the best matches.

How do I install Hermes Tool Slimmer?

Clone the repository, run scripts/install-hermes-tool-slimmer.sh, then check the result with hermes tool-slimmer doctor. The installer installs the package, copies the dashboard plugin, enables the plugin in Hermes and restarts services. On Hermes builds with dashboard plugin install, you can instead paste aliasocracy/hermes-tool-slimmer on the Plugins page.

Does Hermes Tool Slimmer change which tools are allowed?

No. It only selects which tool schemas are sent with a request. Approval prompts, disabled tools and toolsets, auth and runtime safety policy are untouched.