CtrlK
BlogDocsLog inGet started
Tessl Logo

tooluniverse-custom-tool

Add custom local tools to ToolUniverse alongside the 1000+ built-in tools. Covers JSON-config tools (simplest, no code), Python class tools (REST/SOAP/GraphQL APIs, computational logic), and best-practices for return schemas. Use for wrapping new APIs, adding domain-specific computations, or contributing tools to the registry.

80

Quality

100%

Does it follow best practices?

Run evals on this skill

Adds up to 20 points to the overall score

View guide

SecuritybySnyk

Passed

No findings from the security scan

SKILL.md
Quality
Evals
Security

Quality

Content

100%

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

A well-structured skill body that uses a decision table and executable code to guide users through three tool-creation paths, with explicit install/test/verify checkpoints and validation gotchas. Detail is correctly pushed to two real one-level-deep reference files, keeping the overview lean.

DimensionReasoningScore

Conciseness

Lean, action-dense body — a decision table, tight code blocks, and targeted notes ("Gotchas: ... Use 2-4 broad keywords") with no exposition of concepts Claude already knows; every section earns its tokens, matching the "lean and efficient" score 3 anchor rather than the padded score 2 anchor.

3 / 3

Actionability

Fully executable, copy-paste-ready guidance: complete JSON and Python class examples plus concrete commands ("mkdir -p .tooluniverse/tools", "tu test MyAPI_search '{\"q\": \"test\"}'", "pip install -e /path/to/my_project_root"), satisfying the score 3 anchor.

3 / 3

Workflow Clarity

Each path has a clear sequence with explicit validation checkpoints — the "Install and verify" block ("pip install -e" → "cd ... MUST run from plugin repo directory" → "tu test" → "tu info MyAPI_search to confirm the tool loaded") and the tu test auto-checks plus manual-verification gotchas form a real validate→fix→retry feedback loop, matching the score 3 anchor.

3 / 3

Progressive Disclosure

SKILL.md is an overview that offloads full field/class references to clearly signaled one-level-deep links ("see [references/json-tool.md]", "see [references/python-tool.md]"), both of which are real bundle files; content is appropriately split with easy navigation, the score 3 anchor.

3 / 3

Total

12

/

12

Passed

Description

100%

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

A concise, third-person description that states concrete capabilities and gives explicit "Use for ..." trigger guidance for the ToolUniverse custom-tool niche. It cleanly answers both what the skill does and when to invoke it, with low conflict risk.

DimensionReasoningScore

Specificity

Lists multiple concrete actions in third person — "Add custom local tools", "wrapping new APIs", "adding domain-specific computations", "contributing tools to the registry" — matching the multi-action anchor rather than the single-domain score 2 anchor.

3 / 3

Completeness

Explicitly answers both what ("Covers JSON-config tools ... Python class tools ... best-practices for return schemas") and when ("Use for wrapping new APIs, adding domain-specific computations, or contributing tools to the registry"), the exact score 3 anchor pattern.

3 / 3

Trigger Term Quality

The "Use for wrapping new APIs, adding domain-specific computations, or contributing tools to the registry" clause covers natural phrasings a user would actually say ("wrap an API", "add a computation", "contribute a tool"); not the score 2 anchor because it is not missing common variations, though "registry" leans slightly technical.

3 / 3

Distinctiveness Conflict Risk

The "Add custom local tools to ToolUniverse" niche with its ToolUniverse-scoped triggers is clearly distinguishable and unlikely to fire for unrelated skills; not score 2 because the domain and triggers are specific rather than merely "somewhat specific".

3 / 3

Total

12

/

12

Passed

Validation

100%

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation16 / 16 Passed

Validation for skill structure

No warnings or errors.

Repository
mims-harvard/ToolUniverse
Reviewed

Table of Contents

Is this your skill?

If you maintain this skill, you can claim it as your own. Once claimed, you can manage eval scenarios, bundle related skills, attach documentation or rules, and ensure cross-agent compatibility.