# Test notes: Agent Plugins and Codex

Date: 10 August 2026

## Purpose

See whether one existing read-only Open for Agents capability could be packaged for Agent Plugins 1.0 and used through Codex without changing its rules.

## Tested capability

- Name: `search_documentation`
- Version: `1.0.0`
- Classification: read-only
- Required input: `query`
- Maximum query length: 200 characters
- Optional input: `current_page_resource_id`
- Maximum results: 5
The test used a small fictional documentation set. It had no connection to production, customer information, a production database or a model provider.

## Package and client

- [Agent Plugins specification](https://agent-plugins.org/specification): 1.0.0 Working Draft
- Tested client: Codex CLI 0.147.0-alpha.6.5

The package contained the portable Agent Plugins files, a Skill and a small MCP server. Codex also needed two client-specific configuration files to present the package and start the server. Those files did not change the tool name, inputs, read-only status, limits or authority.

## Results

- Codex installed and discovered the package, Skill and MCP tool.
- A valid documentation search returned three relevant results.
- Empty and oversized queries, unexpected arguments and unknown tools were rejected.
- Breaking the Skill did not give the tool any additional authority.
- Breaking the tool configuration did not corrupt the Skill.
- Removing the package also removed the tool and stopped its local server.
- No model or model provider was used.

## Conclusion

The test showed that one reviewed capability could be packaged for Agent Plugins and used through Codex while preserving its rules. It did not prove compatibility with other clients, remote distribution, signing, production authentication, marketplace publication or installation without the small Codex-specific adapter.

No production system or customer data was used or changed.