Drug Synergy (ToolUniverse Claude Skill)

A ToolUniverse agent skill that classifies a two-drug combination as synergistic, additive, or antagonistic by applying the appropriate standard reference model to measured effect data.

   
Type Claude Skill (one of ToolUniverse’s pre-built agent skills)
Supplier Zitnik Lab, Harvard Medical School
Availability GA — part of the ToolUniverse skills collection (skills/tooluniverse-drug-synergy/)
Pricing Free / OSS (Apache-2.0); the synergy calculators run locally over user-supplied effect data
Capabilities Read-only — drives ToolUniverse tool calls; no data writes
Verified works · 2026-07-20
Security cleared · 2026-07-20 — provenance matches Zitnik Lab, Apache-2.0, skill dir confirmed, no OSV advisories

How to install

This skill calls ToolUniverse tools, so the ToolUniverse MCP server must be installed first (see the ToolUniverse page). Simplest registration:

claude mcp add --transport stdio tooluniverse -- uvx tooluniverse

Then add the skills:

  • Claude Code — install the whole skill collection (the skill resolves as tooluniverse-drug-synergy): 
    npx skills add mims-harvard/ToolUniverse
  • Manual / other agents — copy just this skill directory into your skills folder: 
    git clone https://github.com/mims-harvard/ToolUniverse
cp -r ToolUniverse/skills/tooluniverse-drug-synergy ~/.claude/skills/

The skill sets disable-model-invocation: true upstream, so invoke it explicitly (e.g. ask Claude to “use the drug-synergy skill”) rather than relying on automatic dispatch.

What it does

Guides a four-step synergy assessment:

  • Model selection — pick the reference model from the data available, from a single dose pair (Bliss) up to a full dose-response matrix (ZIP).
  • Baseline explanation — describe each model’s additivity baseline (Bliss independence, HSA, Loewe additivity), noting that Bliss and Loewe can legitimately disagree for a given combination.
  • Calculation — run the ToolUniverse calculator: DrugSynergy_calculate_bliss, DrugSynergy_calculate_hsa, DrugSynergy_calculate_loewe, DrugSynergy_calculate_zip, DrugSynergy_calculate_ci (Chou-Talalay Combination Index).
  • Interpretation — apply standard thresholds (synergy > +10, additive −10 to +10, antagonism < −10 on a 0–100 scale; CI < 1 indicates synergy) and flag pitfalls such as scale mismatch, ceiling effects, and model-selection bias.

Primary use cases: scoring combination-screen results, deciding between Bliss/Loewe/ZIP for a given dataset, sanity-checking reported synergy claims.

Notes

It is a reasoning layer over ToolUniverse; without the MCP server registered, the tool calls fail. The skill operates on user-supplied effect data — single-drug and combination effects on a consistent inhibition scale, with ≥ 3 measurable-effect dose points per drug for Loewe/CI/ZIP — rather than pulling combination data from a database. ToolUniverse ships ~68 such skills; the research, repurposing, and target-validation workflows are catalogued separately.

Sources

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