System Prompts That Work For Hermes

Different model families are tuned with different prompt formats and different defaults. A system prompt that produces clean output on GPT or Claude may produce verbose, hedged output on Hermes — or vice versa. Treat moving from one model to another the way you'd treat moving from one IDE to another: same job, different ergonomics.

Hermes-friendly patterns

1. 1Direct, imperative role statements work better than role-play. 'You analyze sales emails' beats 'You are an experienced sales analyst with 20 years of'.
2. 2Explicit format directives matter — say 'output one JSON object per line, no commentary' rather than hoping the model infers it.
3. 3Examples in the system prompt help more than abstract descriptions. One worked example beats three sentences of explanation.
4. 4Anti-rules in plain language work — 'never wrap output in code fences' is honored.
5. 5Tool grammar follows the model card exactly. Skipping or improvising the format reduces tool-call reliability sharply.

What tends to fail

• Long, narrative role prompts — Hermes responds with similarly long, narrative output.
• Implicit format instructions — the model often defaults to markdown, code fences, or commentary unless told otherwise.
• Persona-heavy prompts — they shift voice but rarely improve task quality.
• Multiple competing system instructions — Hermes will often follow the first or the last and ignore the middle.

A skeleton you can reuse

Applied exercise

1. 1Take one system prompt that works well in your current frontier model.
2. 2Run it on Hermes unchanged. Note where the output drifts.
3. 3Rewrite using the skeleton above — direct role, explicit format, one example, anti-rules.
4. 4Compare side by side. Save the rewrite as your Hermes-version of that prompt.

The big idea: Hermes deserves its own prompt library. Direct, explicit, and exemplified beats narrative and persona.