Skill Trigger

The skill-trigger evaluator detects whether a Claude Code agent invoked a specific skill during task execution. Use it to test that an agent correctly recognizes when a skill is applicable and triggers it as its first action.

Configuration

assertions:
  - type: skill-trigger
    skill: commit
    should_trigger: true

Properties

Property	Type	Required	Default	Description
skill	string	Yes	—	The skill name to detect. Case-sensitive substring match against the tool input.
should_trigger	boolean	No	true	Whether the skill is expected to trigger. Set to false for negative test cases.

Detection Logic

Only the first tool call in the agent’s response is examined. Subsequent tool calls are ignored.

First Tool Call	Pass Condition
Skill tool	input.skill contains the skill name (case-sensitive substring)
Read tool	input.file_path contains the skill name (case-sensitive substring)
Any other tool	Not triggered

When should_trigger: false, the pass/fail logic is inverted — the assertion passes if the skill was not triggered.

Examples

Positive Test Case

Assert that the agent triggers the commit skill when asked to commit changes:

tests:
  - id: triggers-skill
    input: "Commit my changes"
    assertions:
      - type: skill-trigger
        skill: commit
        should_trigger: true

Negative Test Case

Assert that the agent does not trigger the commit skill for an unrelated prompt:

tests:
  - id: no-false-trigger
    input: "What time is it?"
    assertions:
      - type: skill-trigger
        skill: commit
        should_trigger: false

Combined Positive and Negative Cases

tests:
  - id: triggers-on-commit-request
    input: "Commit my changes"
    assertions:
      - type: skill-trigger
        skill: commit
        should_trigger: true

  - id: no-trigger-on-unrelated-request
    input: "What time is it?"
    assertions:
      - type: skill-trigger
        skill: commit
        should_trigger: false

  - id: triggers-on-push-request
    input: "Push my branch"
    assertions:
      - type: skill-trigger
        skill: push
        should_trigger: true

Role in Transpilation

The skill-trigger evaluator is the mechanism the EVAL.yaml transpiler uses to route test cases into per-skill evals.json files. When a test case contains a skill-trigger assertion, the transpiler places that test case into the eval file for the named skill, with should_trigger set accordingly.

This makes skill-trigger a first-class part of the EVAL.yaml format for skill-based evaluation workflows.

Example transpiler routing:

A test with type: skill-trigger / skill: commit is placed into the commit skill’s evals.json:

# EVAL.yaml (source)
tests:
  - id: commit-trigger
    input: "Commit my changes"
    assertions:
      - type: skill-trigger
        skill: commit
        should_trigger: true

// .agentv/skills/commit/evals.json (transpiled output)
{
  "tests": [
    {
      "id": "commit-trigger",
      "input": "Commit my changes",
      "should_trigger": true
    }
  ]
}

Scoring

Outcome	Score
Skill triggered and should_trigger: true	1.0
Skill not triggered and should_trigger: false	1.0
Skill triggered and should_trigger: false	0.0
Skill not triggered and should_trigger: true	0.0

Next Steps

• Tool Trajectory - Validate full tool call sequences
• Code Judge - Custom script evaluation
• Evaluators Reference - All evaluator types