# GCP Agent Tool Trajectory Evaluator

> Provides custom Python metrics for configuring Vertex AI Gen AI Evaluation to measure Trajectory Precision, Recall, and Order Match.

- Skill: `googlecloudplatform/gcp-agent-tool-trajectory-evaluator` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add googlecloudplatform/gcp-agent-tool-trajectory-evaluator`
- Raw SKILL.md: https://api.skillmd.com/api/skills/googlecloudplatform/gcp-agent-tool-trajectory-evaluator/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: DevOps & Infra
- Author: GoogleCloudPlatform (https://skillmd.com/u/googlecloudplatform)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/googlecloudplatform/gcp-agent-tool-trajectory-evaluator

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# gcp-agent-tool-trajectory-evaluator

This skill provides the specialized Python logic needed to evaluate how an agent uses its tools. Grounded in `evaluation_blog.md`, it moves beyond "Did the tool run?" to "Were the tools used correctly and efficiently?"

## Usage

Ask Antigravity to:
- "Implement Trajectory Precision and Recall metrics"
- "Set up an Order Match metric for my multi-step agent"
- "Add a custom trajectory scorer to my Vertex AI evaluation"

## Metric Definitions

1. **Trajectory Precision**: Measures what percentage of called tools were actually specified in the reference.
2. **Trajectory Recall**: Measures what percentage of required tools were successfully called by the agent.
3. **In-Order Match**: Checks if the required tools were called in the correct sequence (even if other non-essential tools were called in between).

## implementation Pattern

Refer to `scripts/trajectory_metrics.py`. These functions are designed to be serialized and passed to Vertex AI via `CustomCodeExecutionSpec`.